Data writing method, data reading method, magneto-electric disk, storage system, and magnetic tape

Abstract

The present application relates to the technical field of storage, and discloses a data writing method, a data reading method, a magneto-electric disk, a storage system, and a magnetic tape. The magneto-electric disk performs scalable coding on an original video / audio to obtain base-layer data and enhancement-layer data, and respectively stores data of different layers in magnetic tape regions of a limited length of the magnetic tape in the length direction of the magnetic tape, wherein the magnetic tape regions are longitudinally distributed in the magnetic tape of a limited length. During a video / audio access, the magneto-electric disk preferentially reads the base-layer data, and the amount of data of the base-layer data is relatively small, thereby reducing long tail latency of the magneto-electric disk. Moreover, since the base-layer data is longitudinally distributed in the magnetic tape regions of the limited length, a seek time of a magnetic head is shortened, further reducing the long tail latency of the video / audio access process, and improving video / audio access efficiency.

Description

A method for writing data, a method for reading data, a magnetoelectric disk, a storage system, and a magnetic tape.

[0001] This application claims priority to Chinese Patent Application No. 202510104905.1, filed on January 22, 2025, with the title “A method for writing data, a method for reading data, a magnetoelectric disk, a storage system and a magnetic tape”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of storage technology, and in particular to a data writing method, a data reading method, a magneto-electric disk, a storage system, and a magnetic tape. Background Technology

[0003] Magnetic tape is a strip of material containing a magnetic layer used to record sound, images, digital signals, or other signals. Magnetic media, such as magnetic powder, are attached to the tape for data storage. In storage technology, magnetic tape is the best choice for backup and archiving scenarios due to its low cost, high reliability, and security. Taking a tape drive as an example, a tape drive is a single-drive product consisting of a tape drive and a tape. Based on the mechanical characteristics of data storage in a tape drive, the tape drive drives the tape to reel in, aligning the read / write head with the target position on the tape, and then reading the data stored at that target position. When the data stored on the tape is video data, video has high latency requirements, but the image data in video is large, and the tape read / write speed is slow, resulting in a large long-tail latency in video transmission. Summary of the Invention

[0004] This application provides a data writing method, a data reading method, a magnetoelectric disk, a storage system, and a magnetic tape, which helps to reduce the access latency and long-tail latency of audio and video data in magnetic tape and extend the service life of the magnetic tape.

[0005] The following technical solution was adopted in this application.

[0006] Firstly, this application provides a data writing method. This data writing method is applied to a magnetoelectric disk, which includes a processor and a magnetic tape. The data writing method provided by this application includes: acquiring audio and video data, which includes video data and / or audio data; writing basic layer data of the audio and video data into a first magnetic tape region; and writing enhancement layer data of the audio and video data into a second magnetic tape region of the first magnetic tape. The basic layer data and enhancement layer data are obtained by scalable encoding of the audio and video data. For example, the enhancement layer data is obtained by processing the audio and video data based on the basic layer data, and the quality of the audio and video data obtained based on the basic layer data and enhancement layer data is higher than the quality of the audio and video data obtained based on the basic layer data. The first magnetic tape includes multiple wraps, wherein each wrap includes K sub-wraps, and the first magnetic tape region and the second magnetic tape region are arranged side-by-side along the length of the first magnetic tape. The first magnetic tape region includes M sub-wraps, where the M sub-wraps come from different wraps, K≥2, and M≥2. The second magnetic tape region includes N sub-wraps, where the N sub-wraps come from different wraps, and N≥2.

[0007] In the first aspect of this application, the magneto-electric disk can store the base layer data and enhancement layer data obtained by scalable encoding of audio and video separately. For example, the data of different layers can be stored separately along the length of the magnetic tape into a finite-length area of ​​the tape, with the tape area distributed longitudinally within the finite-length tape. During audio and video access, the magneto-electric disk prioritizes reading the base layer data, and since the amount of base layer data is relatively small, the long-tail latency of the magneto-electric disk can be reduced. Furthermore, because the base layer data is distributed longitudinally within the finite-length tape area, the head seek time is reduced, further reducing the long-tail latency of the audio and video access process and improving the efficiency of audio and video access.

[0008] In conjunction with the data writing method provided in the first aspect, in one optional implementation, the data writing method provided in the first aspect of this application further includes: writing a copy of the basic layer data to a third tape region and writing a copy of the enhancement layer data to a fourth tape region.

[0009] In the first optional scenario, the first, third, and fourth tape regions are arranged side-by-side along the length of the first tape. The third tape region includes multiple sub-wraps derived from different wrappers in the first tape, and the fourth tape region also includes multiple sub-wraps derived from different wrappers in the first tape. The magneto-electric disk employs a multi-copy redundant storage strategy to store multi-layered audio and video data. This allows the multi-layered data and its copies to be stored in different tape regions along the length of the tape, enabling the read / write head to more easily address the base layer data on the tape. This reduces audio and video access latency and further reduces long-tail latency in the audio and video access process, thereby improving audio and video access efficiency.

[0010] In the second optional scenario, the third and fourth tape regions are arranged side-by-side along the length of the second tape. The third tape region includes multiple sub-wraps derived from different wraps within the second tape, and the fourth tape region also includes multiple sub-wraps derived from different wraps within the second tape. The magneto-electric disk employs a multi-copy redundant storage strategy to store multi-layered audio and video data. This allows multi-layered data and its copies to be stored in different tape regions on different tapes. Furthermore, the different tape regions containing multi-layered data within the same tape are arranged side-by-side along the length of the tape. This enables the magnetic head to more easily address the base layer data on the tape, thereby reducing audio and video access latency and further reducing long-tail latency in the audio and video access process, thus improving audio and video access efficiency.

[0011] In conjunction with the data writing method provided in the first aspect, in one optional implementation, the first magnetic head is located in the first magnetic tape area when the first magnetic tape is not accessed. In the first aspect of this application, placing the first magnetic head in the first magnetic tape area where the basic layer data is located reduces the addressing distance of the first magnetic head during audio / video access, which helps to reduce the addressing time of the first magnetic head, thereby reducing the long-tail latency of the audio / video access process and improving the efficiency of audio / video access.

[0012] In conjunction with the data writing method provided in the first aspect, in one optional implementation, the second magnetic head is located in the third magnetic tape region when the second magnetic tape is not accessed. In the first aspect of this application, by setting the second magnetic head in the third magnetic tape region where the basic layer data is located, the addressing distance of the second magnetic head is reduced during audio / video access, which helps to reduce the addressing time of the second magnetic head, thereby shortening the long-tail latency of the audio / video access process and improving the efficiency of audio / video access.

[0013] In conjunction with the data writing method provided in the first aspect, in one optional implementation, when the first tape is not accessed, the first magnetic head is located in the first tape region; and when the second tape is not accessed, the second magnetic head is located in the third tape region. In the first aspect of this application, different magnetic heads are each located in the tape region where the basic layer data is located in the tape corresponding to the magnetic head. During audio / video access, the magnetic head closest to the target address can be selected to read the basic layer data of the audio / video, further reducing the addressing distance of the magnetic head and reducing the addressing time of the magnetic head, thus shortening the long-tail latency of the audio / video access process.

[0014] Secondly, this application provides a data reading method. This data reading method is applied to a magnetoelectric disk or a storage system including a magnetoelectric disk, the magnetoelectric disk including a processor and a magnetic tape. The data reading method provided in the second aspect of this application includes: obtaining a read request from a client, the read request including an identifier of a target audio / video. In response to the read request, reading base layer data of the target audio / video from a first magnetic tape region based on the identifier of the target audio / video; wherein the magnetic tape includes multiple wraps, one of the multiple wraps includes K sub-wraps, K≥2; the first magnetic tape region includes M sub-wraps, the M sub-wraps coming from different wraps, M≥2; the target audio / video is scalably encoded to obtain base layer data and enhancement layer data, the enhancement layer data being stored in: a second magnetic tape region arranged side-by-side with the first magnetic tape region along the length of the magnetic tape, the second magnetic tape region including N sub-wraps, N≥2; the quality of the audio / video obtained based on the base layer data and the enhancement layer data is higher than the quality of the audio / video obtained based on the base layer data. And, sending the base layer data of the target audio / video to the client.

[0015] In the second aspect of this application, different magnetic tape regions arranged side-by-side along the length of the magnetic tape in the magneto-electric disk are used to store different layers of audio and video data. Since the magnetic tape regions are longitudinally distributed within a finite length of magnetic tape, the magneto-electric disk prioritizes reading the basic layer data during audio and video access. Furthermore, because the basic layer data is longitudinally distributed within the finite length of the magnetic tape region, the head seek time is reduced, further decreasing the long-tail latency during audio and video access and improving access efficiency.

[0016] In conjunction with the data reading method provided in the second aspect, in one optional implementation, after obtaining the client's read request, the data reading method provided in the second aspect of this application further includes: pre-fetching the enhancement layer data of the target audio / video stored in the second tape region of the magnetic tape into a cache; the read / write speed of the cache is greater than the read / write speed of the magnetic tape; and sending the enhancement layer data in the cache to the client. The magnetic disk pre-fetches the enhancement layer data into the cache for later use. Since the read / write speed of the cache is greater than the read / write speed of the magnetic tape, it ensures that when the client receives the basic layer data, it can smoothly play the audio / video based on that basic layer data, thereby improving the audio / video quality by receiving the pre-fetched enhancement layer data from the cache.

[0017] In conjunction with the data reading method provided in the second aspect, in one optional implementation, the enhancement layer data of the target audio / video stored in the second tape region of the magnetic tape is prefetched into the cache, including: obtaining prefetch description information, which includes: the client's transmission bandwidth and / or target resolution. And, based on the prefetch description information, the target enhancement layer data stored in the second tape region of the magnetic tape is written into the cache. The target enhancement layer data includes one or more combinations of the following: spatial domain enhancement layer data of the target audio / video, temporal domain enhancement layer data of the target audio / video, and quality enhancement layer data of the target audio / video. In the second aspect of this application, the magnetic disk, combined with the client's device conditions (such as transmission bandwidth and target resolution), prefetches enhancement layer data matching the client's device conditions into the cache when the client has already obtained the basic layer data of the audio / video. Since the read / write speed of the cache is greater than that of the magnetic tape, with the amount of enhancement layer data remaining unchanged, the data transmission efficiency between the cache and the client is improved, and the access latency and long-tail latency of audio / video transmission are reduced, which is beneficial to improving the access efficiency of audio / video.

[0018] Thirdly, this application provides an audio / video access method. This method is applied to a magneto-electric disk, which includes a processor and a magnetic tape. The method includes: acquiring audio / video data; the audio / video data includes video data and / or audio data; writing basic layer data of the audio / video data to a first magnetic tape region and writing enhancement layer data of the audio / video data to a second magnetic tape region. The basic layer data and enhancement layer data are obtained by scalable encoding of the audio / video data, such that the enhancement layer data is obtained by processing the audio / video data based on the basic layer data, and the quality of the audio / video data obtained based on the basic layer data and enhancement layer data is higher than the quality of the audio / video data obtained based on the basic layer data. The magnetic tape includes multiple wraps, where each wrap includes K sub-wraps. The first and second magnetic tape regions are arranged side-by-side along the length of the magnetic tape. The first magnetic tape region includes M sub-wraps, where the M sub-wraps come from different wraps, K≥2, M≥2. The second magnetic tape region includes N sub-wraps, where the N sub-wraps come from different wraps, N≥2. The method also includes: acquiring a playback request from a client; and in response to the playback request, forwarding the basic layer data stored in the first magnetic tape region to the client.

[0019] In a third aspect of this application, different magnetic tape regions arranged side-by-side along the length of the magnetic tape in the magneto-electric disk are used to store different layers of audio and video data. Since the magnetic tape regions are longitudinally distributed within a finite length of tape, the addressing distance and addressing time of the magnetic head are reduced during audio and video access. The magneto-electric disk prioritizes reading basic layer data, and since the amount of basic layer data is relatively small, the long-tail latency of the magneto-electric disk can be reduced, which is beneficial to improving the access efficiency of audio and video. During the transmission of basic layer data, the magneto-electric disk also prefetches enhancement layer data into a cache for later use. Since the read / write speed of the cache is greater than that of the magnetic tape, it ensures that when the client receives basic layer data, it can smoothly play audio and video based on that basic layer data. Furthermore, the prefetched enhancement layer data in the cache can improve the audio and video quality.

[0020] Combining the data writing method provided in the first aspect, the data reading method provided in the second aspect, or the audio / video access method provided in the third aspect, in one optional implementation, the storage capacity of one sub-wrap among M sub-wraps is the same as the storage capacity of one sub-wrap among N sub-wraps.

[0021] Combining the data writing method provided in the first aspect, the data reading method provided in the second aspect, or the audio / video access method provided in the third aspect, in one optional implementation, the storage capacity of one sub-wrap among M sub-wraps is different from the storage capacity of one sub-wrap among N sub-wraps.

[0022] For example, if the amount of data in the base layer is greater than the amount of data in the enhancement layer, then the storage capacity of one sub-wrap among M sub-wraps is greater than the storage capacity of one sub-wrap among N sub-wraps.

[0023] For example, if the amount of data in the base layer is less than the amount of data in the enhancement layer, then the storage capacity of one sub-wrap among M sub-wraps is less than the storage capacity of one sub-wrap among N sub-wraps.

[0024] Optionally, M is less than or equal to the number of wraps included in the tape. Optionally, N is less than or equal to the number of wraps included in the tape.

[0025] In one optional implementation, the enhancement layer data includes one or more of the following combinations: spatial enhancement layer data, temporal enhancement layer data, and quality enhancement layer data, in combination with the data writing method provided in the first aspect, the data reading method provided in the second aspect, or the audio / video access method provided in the third aspect.

[0026] Fourthly, this application provides a magnetic tape. The magnetic tape includes multiple tape regions. These multiple tape regions include a first tape region and a second tape region arranged side-by-side along the length of the tape. The tape includes multiple wraps, where each wrap includes K sub-wraps, where K ≥ 2. The first tape region includes M sub-wraps, where M sub-wraps come from different wraps and M ≥ 2. The first tape region is used to store the base layer data of the target audio / video; the base layer data of the target audio / video is obtained by scalable encoding of the target audio / video. The second tape region includes N sub-wraps, where N sub-wraps come from different wraps and N ≥ 2. The second tape region is used to store the enhancement layer data of the target audio / video; the enhancement layer data of the target audio / video is obtained by processing the target audio / video based on the base layer data, and the quality of the audio / video obtained based on the base layer data and the enhancement layer data is higher than the quality of the audio / video obtained based on the base layer data.

[0027] In the fourth aspect of this application, a magnetic tape region is used to store basic layer data or enhancement layer data of audio and video. This magnetic tape region and other magnetic tape regions are arranged horizontally side by side and vertically distributed within a finite length of magnetic tape region. Therefore, during the data writing process, multiple concurrent applications write data to the magnetic tape, and the data is arranged sequentially along the length of the magnetic tape, which helps to reduce the access latency of data reading and writing in the magnetic tape and extend the service life of the magnetic tape.

[0028] In conjunction with the magnetic tape provided in the fourth aspect, in one optional implementation, the storage capacity of one sub-wrap among M sub-wraps is the same as the storage capacity of one sub-wrap among N sub-wraps.

[0029] In conjunction with the magnetic tape provided in the fourth aspect, in one optional implementation, the storage capacity of one sub-wrap among M sub-wraps is different from the storage capacity of one sub-wrap among N sub-wraps.

[0030] In conjunction with the magnetic tape provided in the fourth aspect, in one optional implementation, the multiple magnetic tape regions further include a third magnetic tape region and a fourth magnetic tape region arranged side-by-side with the first magnetic tape region along the length of the magnetic tape. The third magnetic tape region is used to store copies of the base layer data, and the multiple sub-wraps included in the third magnetic tape region come from different wraps in the first magnetic tape. The fourth magnetic tape region is used to store copies of the enhancement layer data, and the multiple sub-wraps included in the fourth magnetic tape region come from different wraps in the first magnetic tape. The magnetic tape employs a multi-copy redundant storage strategy to store multi-layer data of audio and video, so that the multi-layer data and its copies are stored in different magnetic tape regions, and the different magnetic tape regions are arranged side-by-side along the length of the magnetic tape, enabling the magnetic head to address the base layer data more smoothly on the magnetic tape, thereby reducing the access latency of audio and video, and further reducing the long-tail latency of the audio and video access process, improving the access efficiency of audio and video.

[0031] Fifthly, this application provides a magnetoelectric disk. The magnetoelectric disk includes: a communication interface, a magnetic tape, a processor, and a magnetic head. The communication interface is used to acquire audio and video data; the audio and video data include one or both of video data and audio data. The magnetic tape includes multiple tape regions, including a first tape region and a second tape region arranged side-by-side along the length of the tape. The magnetic tape has multiple wraps, wherein each wrap contains K sub-wraps, where K ≥ 2. The first tape region includes M sub-wraps, where the M sub-wraps come from different wraps, and M ≥ 2. The second tape region includes N sub-wraps, where the N sub-wraps come from different wraps, and N ≥ 2. The magnetic head is used to access the magnetic tape. The processor is used to collaboratively execute the operational steps of the method provided in any of the optional implementations of the first to third aspects, based on the audio and video data and the magnetic head.

[0032] Sixthly, this application provides a storage system. The storage system includes: a controller and one or more magnetoelectric disks as provided in the fifth aspect. The controller is configured to acquire audio and video data, and to collaboratively execute operational steps of the methods provided in any of the optional implementations of the first to third aspects based on the audio and video data and the magnetoelectric disks.

[0033] In a seventh aspect, this application provides a computer program product. When the computer program product is run in an electronic device, the electronic device executes the operational steps of the method provided in any of the optional implementations of the first to third aspects. This electronic device may be a processor, a magnetodisk, or a storage system.

[0034] Eighthly, this application provides a computer-readable storage medium. The computer-readable storage medium includes computer instructions. When the computer instructions are executed in an electronic device, the electronic device performs the method provided by any of the optional implementations of the first to third aspects. If the electronic device refers to the aforementioned processor, controller, magnetodisk, or storage system.

[0035] The beneficial effects of aspects five through eight can be found in the description of any of the optional implementations in aspects one through four, and will not be repeated here. Based on the implementations provided in the above aspects, this application can be further combined to provide even more implementations. Attached Figure Description

[0036] Figure 1 is a schematic diagram of the structure of a data access system provided in this application.

[0037] Figure 2 is a schematic diagram of the structure of a magnetoelectric disk provided in this application.

[0038] Figure 3 is a structural schematic diagram of a reel 201 and a magnetic tape 210 provided in this application.

[0039] Figure 4 is a schematic diagram of the structure of a magnetic tape 210 provided in this application.

[0040] Figure 5 is a flowchart illustrating a data writing method provided in this application.

[0041] Figure 6 is a schematic diagram of the three data arrangements provided in this application.

[0042] Figure 7 is a flowchart of a data writing method provided in this application.

[0043] Figure 8 is a flowchart illustrating one of the data writing methods provided in this application.

[0044] Figure 9 is a flowchart illustrating one of the data writing methods provided in this application.

[0045] Figure 10 is a schematic diagram of a data arrangement structure provided in this application.

[0046] Figure 11 is a flowchart illustrating a data reading method provided in this application. Detailed Implementation

[0047] The technical solution provided in this application includes: different magnetic tape regions arranged side-by-side along the length of the magnetic tape in a magneto-electric disk for storing different layers of audio and video data. Since the magnetic tape regions are longitudinally distributed within a finite length of magnetic tape, the addressing distance and addressing time of the magnetic head are reduced during audio and video access. The magneto-electric disk prioritizes reading basic layer data, and since the amount of basic layer data is relatively small, the long-tail latency of the magneto-electric disk can be reduced, which is beneficial to improving the access efficiency of audio and video. During the transmission of basic layer data, the magneto-electric disk also prefetches enhancement layer data into a cache for later use. Since the read / write speed of the cache is greater than that of the magnetic tape, it ensures that when the client receives basic layer data, it can smoothly play audio and video based on that basic layer data. Furthermore, the prefetched enhancement layer data in the cache can improve the audio and video quality.

[0048] The technical solutions involved in this application may be applied not only to current magnetic tape technology or storage devices, but also to future magnetic tape technology or storage devices, or to storage systems including magneto-electric disks (MEDs) or storage devices, such as magnetic tape systems or magnetic tape libraries. The terminology used in the embodiments section of this application is only for explaining specific embodiments of this application and is not intended to limit this application. A brief introduction to some concepts that may be involved in this application is provided below.

[0049] Storage medium: A storage material used to record sound, images, digital signals, or other signals. This storage material may include, but is not limited to, magnetic tape, such as a tape-shaped material with a magnetic layer used to record sound, images, digital signals, or other signals. Magnetic tape contains a magnetic medium, such as magnetic powder, for storing data. For example, changes in the magnetic field in this magnetic medium are typically achieved by coating a plastic film substrate (support or backing) with a layer of granular magnetic material or by evaporating and depositing a layer of magnetic oxide or alloy film. The substrate of magnetic tape may include, but is not limited to, paper, celluloid, or polyester film.

[0050] Magnetic head: A component that reads and writes data on magnetic tape using magnetic principles. It is divided into write heads and read heads. Write heads record data by magnetizing the magnetic medium (such as magnetic powder), while read heads read data from the magnetic medium by sensing its magnetic field.

[0051] In this document, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0052] Furthermore, in this application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0053] The following description, in conjunction with the accompanying drawings, first introduces the application scenario of the embodiments of this application. Figure 1 is a schematic diagram of the structure of a data access system provided by this application. The data access system includes a data access device 100 and a storage system 120. In the application scenario shown in Figure 1, users access data through applications. The computer running these applications can be referred to as a "computing device".

[0054] Data access device 100 can be a physical machine, a virtual machine, or a container. The physical machine can include, but is not limited to, one or both a client and a smart NIC. For example, data access device 100 includes a client, such as a host, desktop computer, server, laptop, or mobile device. Another example is that data access device 100 includes a smart NIC. This smart NIC, also known as a smart network adapter, not only performs the network transmission functions of a standard NIC but also provides a built-in programmable and configurable hardware acceleration engine. This improves application performance and significantly reduces CPU consumption in the host connected to the smart NIC, providing more CPU resources for the application. For example, in a highly virtualized environment, the host CPU needs to run open virtual switch (OVS) related tasks. Simultaneously, the host CPU also needs to handle storage, online or offline encryption / decryption of data packets, deep packet inspection, firewalls, complex routing, and other operations. These operations not only consume significant CPU resources but also, due to competition for CPU resources between different services, prevent the services from achieving optimal performance. As a hub connecting various services, smart network interface cards (NICs) accelerate these services.

[0055] In one possible example, data access device 100 accesses storage system 120 via a network to access data; for example, the network may include switch 110.

[0056] In another possible example, the data access device 100 may also communicate with the storage system 120 via a wired connection, such as a Universal Serial Bus (USB) or a Peripheral Component Interconnect Express (PCIe) bus.

[0057] The storage system 120 shown in Figure 1 can be a centralized storage system. A key feature of a centralized storage system is a unified entry point through which all data from external devices passes; this entry point is the engine 121 of the centralized storage system. The engine 121 has management functions, and many advanced functions of the storage system are implemented within it.

[0058] As shown in Figure 1, the engine 121 may contain one or more controllers 1. Figure 1 illustrates this with an example of an engine 121 containing one controller 1. In one possible example, if the engine 121 has multiple controllers 1, any two controllers 1 can have a mirror channel, enabling any two controllers 1 to serve as backups for each other, thereby preventing hardware failures from causing the entire storage system 120 to become unavailable. It should be understood that if the engine 121 includes multiple controllers 1, then the engine 121 can also be referred to as the array controller of the storage system 120.

[0059] Engine 121 also includes a front-end interface 1211 and a back-end interface 1214. The front-end interface 1211 is used to communicate with the data access device 100 to provide data access services to the data access device 100. The back-end interface 1214 is used to communicate with hard drives to expand the capacity of the storage system 120. Through the back-end interface 1214, engine 121 can connect to more hard drives, thereby forming a very large storage resource pool.

[0060] In terms of hardware, as shown in Figure 1, the controller 1 includes at least a processor 1212 and memory 1213. The processor 1212 is a central processing unit (CPU) used to process data access requests from outside the storage system 120 (servers or other storage systems), and also to process requests generated internally within the storage system 120. For example, when the processor 1212 receives write data requests from the data access device 100 through the front-end interface 1211, it temporarily stores the data in these write data requests in memory 1213. When the total amount of data in memory 1213 reaches a certain threshold, the processor 1212 sends the data stored in memory 1213 to at least one of the following hard drives for persistent storage: a mechanical hard drive 1221, a solid-state drive (SSD) 1222, a magnetic disk 200, or another hard drive 1224, through a back-end port.

[0061] Memory 1213 refers to internal memory that directly exchanges data with the processor. It can read and write data at any time and at high speed, serving as temporary data storage for the operating system or other running programs. Memory includes at least two types of memory, such as random access memory (RAM) or read-only memory (ROM). For example, RAM can be dynamic random access memory (DRAM) or storage class memory (SCM). DRAM is a semiconductor memory and, like most random access memory (RAM), is a type of volatile memory device. However, DRAM and SCM are merely illustrative examples in this embodiment; memory can also include other types of RAM, such as static random access memory (SRAM). For read-only memory, examples include programmable read-only memory (PROM) and erasable programmable read-only memory (EPROM). Additionally, memory 1213 can also be a dual in-line memory module (DIMM), i.e., a module composed of dynamic random access memory (DRAM), or an SSD. In practical applications, controller 1 can be configured with multiple memory modules 1213, and memory modules of different types 1213. This embodiment does not limit the number or type of memory modules 1213. Furthermore, memory modules 1213 can be configured to have a power-saving function. The power-saving function means that when the system loses power and then regains power, the data stored in memory modules 1213 will not be lost. Memory with a power-saving function is called non-volatile memory. Memory modules 1213 store software programs, and processor 1212 can run the software programs in memory modules 1213 to manage the hard disk. For example, the hard disk can be abstracted as a storage resource pool, and the storage resource pool can be provided to the server in the form of logical unit numbers (LUNs). Here, LUN is actually the hard disk seen on the server. Of course, some centralized storage systems are also file servers themselves, and can provide shared file services to the server.

[0062] As shown in Figure 1, in this system, engine 121 may not have a hard drive slot; the hard drive needs to be placed in disk enclosure 122, and the back-end interface 1214 communicates with disk enclosure 122. The back-end interface 1214 exists in the form of an adapter card within engine 121. Two or more back-end interfaces 1214 can be used simultaneously on one engine 121 to connect multiple disk enclosures. Alternatively, the adapter card can be integrated onto the motherboard, in which case it can communicate with processor 1212 via the PCIe bus.

[0063] It should be noted that only one engine 121 is shown in Figure 1. However, in actual applications, the storage system may contain two or more engines 121, and redundancy or load balancing may be performed among the multiple engines 121.

[0064] The disk enclosure 122 includes a control unit 1225 and several hard drives. The control unit 1225 can have various forms. In one case, the disk enclosure 122 is an intelligent disk enclosure, as shown in Figure 1. The control unit 1225 includes a CPU and memory. The CPU is used to perform address translation and data reading / writing operations. The memory is used to temporarily store data to be written to the hard drive or to read data from the hard drive to be sent to the controller 1. In another case, the control unit 1225 is a programmable electronic component, such as a data processing unit (DPU). A DPU has the versatility and programmability of a CPU, but is more specialized, capable of efficiently operating on network packets, storage requests, or analysis requests. A DPU differs from a CPU by its high degree of parallelism (the ability to handle a large number of requests). Optionally, the DPU can also be replaced by a graphics processing unit (GPU), an embedded neural network processing unit (NPU), or other processing chips. Typically, there can be one, two, or more control units 1225. The functions of the control unit 1225 can be offloaded to the network interface card 1226. In other words, in this embodiment, the disk enclosure 122 does not contain a control unit 1225; instead, the network interface card (NIC) 1226 performs data reading and writing, address translation, and other computational functions. In this case, the NIC 1226 is a smart NIC. It can include a CPU and memory. The CPU performs address translation and data reading / writing operations, while the memory temporarily stores data to be written to the hard drive or reads data from the hard drive to be sent to the controller 1. The NIC 1226 can also include a programmable electronic component, such as a digital processing unit (DPU). There is no hierarchical relationship between the NIC 1226 and the hard drives in the disk enclosure 122; the NIC 1226 can access any hard drive in the disk enclosure 122 (such as the mechanical hard drive 1221, solid-state drive 1222, magnetic disk 200, and other hard drives 1224 shown in Figure 1). Therefore, expanding the hard drive is more convenient when storage space is insufficient.

[0065] In this embodiment, the magnetoelectric disk 200 refers to a memory that includes a magnetic tape medium. In hardware implementation, the magnetoelectric disk may include, but is not limited to, a magnetic head, a magnetic tape, and a magnetic tape driver. The magnetic tape driver can be used to drive the magnetic tape for winding, and the magnetic head can access the magnetic tape during the winding process, such as writing data to or reading data from the magnetic tape. Specific implementation details of the magnetoelectric disk can be found in the embodiments shown in Figures 2 to 4 below, and will not be elaborated upon here.

[0066] Depending on the type of communication protocol between engine 121 and disk enclosure 122, disk enclosure 122 may be a serially attached small computer system interface (SAS) disk enclosure, an NVMe (Non-Volatile Memory Express) disk enclosure, or other types of disk enclosures. SAS disk enclosures use the SAS 3.0 protocol, and each enclosure supports 25 SAS hard drives. Engine 121 connects to disk enclosure 122 via an onboard SAS interface or a SAS interface module. NVMe disk enclosures function more like a complete computer system, with NVMe hard drives inserted into them. The NVMe disk enclosure then connects to engine 121 via an RDMA port. In some cases, engine 121 may also be referred to as a hard drive management device or storage controller.

[0067] In terms of hardware implementation, the disk enclosure 122 can be installed in the storage system, or the disk enclosure 122 can be encapsulated and set up independently. When the disk enclosure 122 exists independently, it can also be called a storage device or storage system, such as a magnetoelectric storage system, etc. This application does not limit it in this way.

[0068] In one alternative implementation, the storage system 120 is a centralized storage system integrating disk and controller. The storage system 120 does not have the aforementioned disk enclosure 122, and the engine 121 manages multiple hard drives connected via hard drive bays. The functionality of the hard drive bays can be implemented by the backend interface 1214.

[0069] In some alternative implementations, storage system 120 is a distributed storage system. The distributed storage system includes a cluster of compute nodes and a cluster of storage nodes. The compute node cluster includes one or more compute nodes that can communicate with each other. A compute node can be a server, desktop computer, or controller of a storage array, etc. In terms of hardware, a compute node can include a processor, memory, and a network interface card (NIC), etc. The processor is a CPU used to process data access requests from outside the compute node or requests generated internally within the compute node. For example, when the processor receives a write data request from a user, it temporarily stores the data in the write data request in memory. When the total amount of data in memory reaches a certain threshold, the processor sends the data stored in memory to the storage node for persistent storage. In addition, the processor is also used for data computation or processing, such as metadata management, deduplication, data compression, virtualization of storage space, and address translation. In the embodiments provided in this application, the storage node can be a magnetic disk or other types of hard disk, etc. It is understood that the storage system described in the embodiments of this application can be a distributed storage system integrating storage and computing, or a distributed storage system with separate storage and computing; this application does not limit this.

[0070] For example, a distributed storage system can be implemented using network attached storage (NAS) technology. NAS refers to a network storage architecture that provides storage resources through file-level data access and sharing over an Internet Protocol (IP) network. In a NAS scenario, the NAS is an external device for the server / host, used to provide file-level storage space for the server / host in the distributed storage system.

[0071] It is worth noting that the above examples are merely possible implementations of the data access system provided in this embodiment and should not be construed as limiting this application. For example, in the storage system 120 shown in Figure 1, data is stored as files on various hard drives. The files stored on each hard drive constitute a file storage system, which can be, for example, a distributed file system, such as a network file system (NFS). NFS is both a distributed file system and a network protocol used for accessing and sharing files between devices on the same local area network. For example, a NAS system can be implemented using the NFS protocol. A network file system is a low-cost network file sharing option that allows users and applications to access, store, and update files on remote computers, just like using direct-attached storage. A network file system uses the Remote Procedure Call (RPC) protocol to route requests between clients and servers. Although participating devices need to support a network file system, they do not need to know the details of the network. It is worth noting that RPC can be insecure, therefore a network file system should only be deployed on trusted networks behind firewalls. Although Windows supports this protocol, it is primarily used in Linux environments.

[0072] Regarding the aforementioned magnetoelectric disk 200, this application provides an optional example, as shown in Figure 2, which is a schematic diagram of the structure of a magnetoelectric disk provided in this application. This magnetoelectric disk 200 can be used to implement the functions described above. In this document, the magnetoelectric disk may also be referred to as a magnetic tape media storage device, magnetic tape drive, integrated magnetic tape device, integrated magnetic tape disk, integrated magnetic tape drive, or magnetic tape drive equipment, etc., and this application does not limit it to these terms.

[0073] The magnetoelectric disk 200 is described below with reference to Figure 2. It includes a magnetic tape 210, a magnetic tape drive 220, a magnetic head 230, a reel 201, a roller 202, a base 203, a processor 240, and a cache 241.

[0074] The reel 201 and the base 203 are rotatably connected, and the magnetic tape 210 is wound onto the reel 201.

[0075] Regarding the structural relationship between the reel 201 and the magnetic tape 210, an exemplary description is provided below with reference to Figure 3, which is a schematic diagram of the structure of the reel 201 and the magnetic tape 210 provided in this application. Referring to Figure 3, the reel 201 includes a spool 2013, a first cover plate 2011, and a second cover plate 2012. The spool 2013 is rotatably connected to the base 203 shown in Figure 2. The magnetic tape 210 is located between the first cover plate 2011 and the second cover plate 2012. The first cover plate 2011 and the second cover plate 2012 can constrain the magnetic tape 210, preventing it from detaching from the spool 2013. During the rotation of the spool 2013, the first cover plate 2011 and the second cover plate 2012 rotate synchronously.

[0076] The first cover plate 2011 can be a circular plate structure as shown in Figure 3, and the second cover plate 2012 can be a circular plate structure as shown in Figure 3.

[0077] The embodiments of this application do not limit the shape of the first cover plate 2011 and the second cover plate 2012. For example, the first cover plate 2011 can be a circular, square, elliptical, or irregularly shaped plate. Similarly, the second cover plate 2012 can be a circular, square, elliptical, or irregularly shaped plate. The shape of the first cover plate 2011 can be the same as or different from the shape of the second cover plate 2012.

[0078] For example, the connection between the first cover plate 2011 and the roll 2013 can be achieved by welding, snap-fitting, or bonding. Similarly, the connection between the second cover plate 2012 and the roll 2013 can be achieved by welding, snap-fitting, or bonding.

[0079] Please refer to Figure 2. The magnetodisc 200 includes two reels 201. The first end of the magnetic tape 210 is wound on one reel 201, and the second end of the magnetic tape 210 is wound on the other reel 201.

[0080] During the tape winding process of the magnetic tape 210, in order to prevent the magnetic head from tearing the tape 210, the roller 202 in the magneto-disk 200 can be used to support the tape body of the magnetic tape 210, so that the friction between the magnetic tape 210 and the magnetic head is reduced during the winding process, which is beneficial to improving the service life of the magnetic tape 210.

[0081] As can be seen from the embodiments provided in Figures 2 and 3, the magnetic tape 210 is used to store data, and the magnetic tape driver 220 is used to drive the magnetic tape 210 to reel in.

[0082] The structure of the magnetic tape 210 is illustrated below with reference to Figure 4, which is a schematic diagram of the structure of a magnetic tape 210 provided in this application. In hardware implementation, the magnetic tape 210 may include one or more data bands, such as data band 1 to data band 4. The data bands are data tracks on the magnetic tape 210. Different data bands are separated and positioned by servo tapes, and multiple data bands are arranged side-by-side along the length of the magnetic tape 210. Each data band contains multiple wraps, representing data transmission from one end of the magnetic tape 210 to the other.

[0083] For example, magnetic tape 210 includes wrap1 to wrap8. Each wrap includes one or more tracks, and each track is accessed by a read head / write head. The number and size of data tapes in magnetic tape 210 depend on the generation and capacity of the tape. Wrap is a term used in magnetic tape, and wrap refers to the path the head travels on a data tape.

[0084] Taking data tape 1 in magnetic tape 210 as an example, data tape 1 includes wrap1 and wrap2. Wrap1 includes multiple tracks, such as track 1 and track 2. In magnetic tape 210, different tracks are arranged side by side along the width direction of magnetic tape 210. A track is a magnetic area in the magnetic tape used for recording data. In magnetic tape technology, data storage on magnetic tape 210 is achieved by magnetizing the tracks with the magnetic head 230.

[0085] In addition, the magnetic tape 210 may also include more or fewer wraps, such as the magnetic tape 210 including H wraps, where H≥1 and H is an integer.

[0086] The magnetic tape 210 shown in Figure 4 above is only an optional embodiment provided by this application. Depending on the capacity of the magnetic tape 210 and user needs, the magnetic tape 210 may have more or fewer data tapes, or the magnetic tape 210 may have more or fewer tracks. This application does not limit this.

[0087] The magnetic head in the magneto disk 200 accesses the magnetic tape 210 during the tape rewinding process. The processor 240 is used to control the speed at which the tape drive 220 drives the magnetic tape 210 according to the I / O stream, and to control the magnetic head 230 to slide to access the tape area in the magnetic tape 210.

[0088] In this embodiment, the processor 240 is a CPU used to process data access requests (such as I / O requests) or task requests from outside the magneto-electric disk 200 (servers or other storage systems), and also to process requests generated internally by the magneto-electric disk 200. For example, when the processor 240 receives write data requests (write requests) sent by a data access device or host through a front-end interface, it temporarily stores the data in these write data requests in a cache 241. When the total amount of data in the cache 241 reaches a certain threshold, the processor 240 stores the data stored in the cache 241 to the magnetic tape 210 for persistent storage through a back-end port.

[0089] In terms of hardware implementation, cache 241 includes flash memory chips (also known as flash memory particles or cache particles), hard disk drives (HDDs), or others. For example, flash memory chips may include: XL-LAND, single-level cell (SLC), multi-level cell (MLC), trinary-level cell (TLC), quad-level cell (QLC), enterprise multi-level cell (eMLC), or others. In the embodiments of this application, cache 241 may also be, for example, DRAM, non-volatile magnetic random access memory (MRAM), resistive random access memory (RRAM), ferroelectric random access memory (FeRAM), high bandwidth memory (HBM), or phase change memory (PCM), etc.

[0090] Solid-state drives (SSDs) are hard drives made using arrays of solid-state electronic storage chips. An SSD consists of a control unit and storage units, such as FLASH chips or DRAM chips. The control unit manages the storage units, virtualizing the storage space provided by the units or performing data read / write operations on different storage units.

[0091] A hard disk drive (HDD) consists of platters, read / write heads, a spindle, a control motor, a head controller, a data converter, memory, and an interface. The read / write head moves radially along the platter to locate a specific position on the platter, and then reads and writes data to that position. In terms of read / write speeds, SSDs generally outperform HDDs.

[0092] Random access memory (DRAM) is a type of semiconductor memory that primarily works by using the amount of charge stored in a capacitor to represent whether a binary bit is 1 or 0.

[0093] Storage-class memory (SCM) is a hybrid storage technology that combines the characteristics of traditional storage devices and memory. SCM can provide faster read and write speeds than hard drives, but its access speed is slower than DRAM, and it is also cheaper than DRAM.

[0094] Resistive Random Access Memory (RRAM) is a novel type of non-volatile memory that stores "0" and "1" by applying pulsed voltages to a thin metal oxide film, creating a large resistance difference. RRAM has a very simple structure, with metal oxide sandwiched between two electrodes, which simplifies the manufacturing process and enables superior performance such as low power consumption and high-speed rewriting.

[0095] Ferroelectric RAM (FeRAM) is a type of random access memory. FeRAM cells primarily consist of capacitors and field-effect transistors (FETs), but these capacitors are not ordinary capacitors; a thin film of crystalline ferroelectric crystal is deposited between its two electrode plates. Early FeRAMs used two FETs and two capacitors per cell, known as "2T2C" (two-FET, two-capacitor), with each cell including a data bit and its own reference bit. "1T1C" (one-FET, one-capacitor) cells use one FET and one capacitor. In 1T1C FeRAM, all data bits share the same reference bit, instead of using separate reference bits for each data bit. 1T1C FeRAM products are less expensive and have larger capacities.

[0096] High-bandwidth memory (HBM), also known as high-speed RAM, is a high-performance DRAM based on a three-dimensional stacking process. It is suitable for applications with high memory bandwidth requirements, such as GPUs, network switching and forwarding devices (such as routers and switches). HBM typically consists of multiple stacked double-data-rate synchronous dynamic random access memory (DDR) chips and a GPU. The HBM stack is not physically integrated with the CPU or GPU; instead, it is compactly and rapidly connected through an intermediary layer. HBM possesses characteristics almost identical to on-chip integrated RAM, thus offering higher speed and bandwidth.

[0097] Phase change memory (PCM) stores data by utilizing the difference in conductivity exhibited by special materials when they transform between crystalline and amorphous states. PCM typically utilizes the significant difference in conductivity between crystalline and amorphous states of chalcogenides to store data.

[0098] In this embodiment, cache 241 includes multiple storage areas. A storage area refers to a portion of the storage space provided by cache 241. The storage areas are divided according to their function; for example, these multiple storage areas may include a write storage area (also called a write cache) and a read storage area (also called a read cache). The write storage area is used to temporarily store data to be written during the write process, and the read storage area is used to temporarily store data to be prefetched during the read process. Whether the write storage area and the read storage area are located in the same cache, or in different caches, this application does not limit this.

[0099] When cache 241 is DRAM, a storage area refers to one or more data pages or cache lines. A page is the smallest unit of data written, such as a page being 4 kilobytes (KB). A cache line is the smallest unit of data stored in cache 241, for example, a cache line being 64 bytes in size.

[0100] When cache 241 is a flash memory chip, a storage area refers to one or more storage blocks. A storage block consists of multiple pages. When a block is full, the processor 240 selects the next block to write data. A block is the smallest unit of data erasure.

[0101] In the case of a cache 241 SSD that supports zoned namespaces (ZNS), a storage zone refers to one or more regions that divide the logical address space of the namespace. For example, a region may have a storage capacity of 4MB, 8MB, or other values.

[0102] In the case of SCM (Supply Chain Management) cache 241, a storage area refers to one or more bytes or blocks. A byte is a group of 8 bits used for data storage. In SCM, storage areas can support data storage using both bytes and blocks simultaneously.

[0103] In the case of cache 241 being HBM, a storage area refers to one or more data pages.

[0104] When cache 241 is PCM, a storage area refers to one or more storage blocks or data pages.

[0105] The memory types described above are merely optional options for the cache 241 and storage area provided in this application embodiment, and should not be construed as limiting this application. In this document, the read / write speed of the cache 241 is greater than the read / write speed of the magnetic tape 210.

[0106] In the magneto-electric disk 200 shown in Figure 2, the processor 240 and cache 241 are configured independently. However, in some optional cases, the cache 241 is integrated into the processor 240 and connected via a PCIe bus, a unified bus (Ubus or UB), or a compute express link (CXL), etc., which is not limited in this application.

[0107] Optionally, the tape drive 220 includes a tape reel motor and a voice coil motor (VCM) motor.

[0108] The tape reel motor is used to drive the magnetic tape 210 to wind along its length. For example, the tape reel motor can be used to drive a drum, causing the magnetic tape wound on the drum to rewind in a first direction, rewind in a second direction, or stop rewinding. The first direction and the second direction are two opposite directions along the length of the magnetic tape.

[0109] The VCM motor is used to drive the magnetic tape 210 to move along the width of the tape 210, so that the magnetic head 230 can access different tracks in the tape 210. The VCM is a direct drive motor, and its working principle includes: a current-carrying coil placed in a magnetic field will generate a force, the magnitude of which is proportional to the current applied to the coil. Based on this principle, the movement of the VCM can be linear or circular.

[0110] Optionally, the tape drive 220 may also include a stepper motor for fine-tuning the winding position or speed of the tape 210 along its length. This stepper motor is a type of electric motor that converts electrical pulse signals into corresponding angular or linear displacements. For each input pulse signal, the rotor rotates by an angle or moves forward one step; the output angular or linear displacement is proportional to the number of input pulses, and the rotational speed is proportional to the pulse frequency. Therefore, a stepper motor is also called a pulse motor.

[0111] It is worth noting that the tape drive 220 described above are merely examples provided in the embodiments of this application and should not be construed as limiting the application. The tape drive 220 may also include devices such as linear motors, hydraulic cylinders, or pneumatic cylinders, which are not limited in this application.

[0112] As an optional implementation, the magnetic head 230 may include one or both of a write head and a read head. The write head records data by magnetizing and changing the magnetic field of the magnetic medium (such as magnetic powder), while the read head reads data from the magnetic medium by sensing its magnetic field.

[0113] In some alternative configurations, the magnetic head 230 may also include a servo head, which may be divided into a write servo head and a read servo head. Taking the read servo head as an example, the read servo head can determine the position information of the tape 210 based on the address in the IO request, and the tape driver 220 can rewind the tape 210 from its current position to the target tape area indicated by the position information, so that the read data head can read the data stored in the target tape area.

[0114] Optionally, the magnetodisk 200 may also deploy an application (APP) and a driver. This application can be used to obtain data access requests (such as read or write requests) or send access responses to the host, such as write or read responses. For example, after the application triggers a read / write operation, the IO data stream is sent to the firmware corresponding to the magnetic tape 210 via the driver. The firmware then issues instructions to control the motor to drive the tape 210 to perform linear addressing. Once the desired tape position is reached, the read / write operation is achieved by the magnetic head through a digital-to-analog converter channel or an analog-to-digital converter channel for encoding and decoding.

[0115] The following description, based on the magnetoelectric disk 200 provided in the foregoing embodiments and in conjunction with FIG. 5, illustrates the data writing method provided in this application. FIG. 5 is a schematic flowchart of a data writing method provided in this application. The data writing method provided in this application is applied to the magnetoelectric disk 200. The hardware implementation of the magnetoelectric disk 200 in FIG. 5 can be referred to the description of FIG. 1 to FIG. 4 above, and will not be repeated here.

[0116] In Figure 5, the magnetic tape 210 includes multiple tape regions arranged side by side. These multiple tape regions include: tape region 1 (first tape region) and tape region 2 (second tape region) arranged side by side along the length of the magnetic tape 210.

[0117] In Figure 5, the magnetic tape 210 includes multiple wraps arranged side-by-side along the width of the tape 210, such as wrap1 to wrap9. Each wrap includes K sub-wraps (sw), where K ≥ 2 and K is an integer. A sub-wrap (sw) refers to a portion of a complete wrap that is used to store data.

[0118] In one alternative example, a tape region refers to a contiguous storage space within a magnetic tape.

[0119] Taking tape region 1 (first tape region) as an example, this first tape region is used to store basic layer data of audio and video. Tape region 1 includes M sub-wraps, and the M sub-wraps come from different wraps. The M sub-wraps are arranged side by side along the width direction of tape 210. Wherein, M≥2, and M is less than or equal to the number of wraps included in tape 210.

[0120] For example, in Figure 5, tape region 1 includes 9 sub-wraps, and these 9 sub-wraps come from different wraps (such as wrap1 to wrap9). For example, these 9 sub-wraps include sw1-1 to sw9-1.

[0121] Taking tape region 2 (second tape region) as an example, this second tape region is used to store audio and video enhancement layer data. Tape region 2 includes N sub-wraps, and the N sub-wraps come from different wraps. These N sub-wraps are arranged side by side along the width direction of tape 210. Wherein, N≥2, and N is less than or equal to the number of wraps included in tape 210.

[0122] For example, in Figure 5, tape region 2 includes 9 sub-wraps, and these 9 sub-wraps come from different wraps (such as wrap1 to wrap9). For example, these 9 sub-wraps include sw1-2 to sw9-2.

[0123] In this embodiment, different magnetic tape regions are used to store data corresponding to different audio and video qualities. These audio and video qualities include one or more of the following combinations: resolution, frame rate, texture information, or quantization parameter (QP).

[0124] Resolution refers to the amount of information stored in an image, such as the number of pixels per inch. Resolution is directly proportional to audio and video quality.

[0125] Frame rate, also known as frame rate or frame frequency, is measured in Hertz (Hz) and refers to the number of images displayed per unit of time. The frame rate is directly proportional to the quality of the audio and video content.

[0126] Texture information refers to the visual characteristics of homogeneous phenomena in an image. It reflects the slowly changing or periodically altered organizational structure of the surface of objects in the image. Image texture information (or simply image texture) is represented by the gray-level distribution of the spatial neighborhood around each pixel, i.e., local texture information. Furthermore, the varying degrees of repetition in local texture information constitute global texture information. The amount of texture information is directly proportional to the quality of audio and video.

[0127] Quantization parameter (QP) refers to the parameter used to map continuous values ​​of a signal into multiple discrete amplitude values. The magnitude of the quantization parameter is inversely proportional to the audio / video quality.

[0128] The above descriptions of audio and video quality are merely optional methods provided in the embodiments of this application and should not be construed as limiting this application.

[0129] In another alternative example, the tape region includes multiple sub-wraps along the width direction of the tape 210, and the storage space within a sub-wrap is contiguous. That is, the tape region includes a finite length of tape body along the length direction of the tape 210, and the data within the tape region is arranged sequentially along the length direction of the tape 210, which helps to reduce data read / write latency in the tape 210 and extend the lifespan of the tape 210.

[0130] Please refer to Figure 5. The data writing method provided in this application embodiment includes S510 to S530.

[0131] S510, Processor 240 acquires audio and video.

[0132] In the embodiments of this application, "audiovisual" is an information application technology term that refers to video, audio, or multimedia content including video and audio.

[0133] In the first alternative example, the audio and video include video data. Video data is a general term encompassing a sequence of multiple consecutive frames, one frame corresponding to one image. In some cases, video data is also simply called video, and its transmission is achieved through video streaming. For example, video streaming can be processed over a network as a stable and continuous stream. A video stream consists of multiple video frames, each corresponding to one image. Image parameters may include color (i) and transparency (alpha), where color information describes the different colors used in the video image, such as red, green, or blue; transparency (alpha) refers to the degree of transparency of a transparent display, that is, the transparency of the background of the display device or screen.

[0134] In the second alternative example, the audio-visual content includes audio data. Audio data refers to digitized sound data. Digitized sound refers to data obtained by analog-to-digital conversion of a continuous analog audio signal from an audio sampling device at a certain frequency. In some cases, audio data is also called audio, and the transmission of audio data is achieved through audio streaming. For example, an audio stream supporting streaming technology can include one or more audio frames carrying audio data to be played.

[0135] In the third alternative example, the audio-visual content includes video data and audio data.

[0136] The above three optional examples are merely optional methods for obtaining audio and video data provided in the embodiments of this application, and should not be construed as limiting this application. Regarding the process of the processor 240 acquiring audio and video data, two optional scenarios are provided below.

[0137] In an alternative scenario, the audio and video are captured by a camera device, which then sends the captured audio and video to a magneto disk 200 or a storage system 120.

[0138] In another alternative scenario, the audio and video are sent to the magneto disk 200 by a video management platform or other device. The video management platform can access the captured video and store or manage the data obtained during the video acquisition process. Furthermore, the video management platform can interact with the user through a video application. This other device may be a host, server, client, or user device, etc., and this application does not limit its scope to these.

[0139] S520: Write the basic layer data of the audio and video to tape area 1 of tape 210.

[0140] The base layer data is obtained by scalable encoding of audio and video.

[0141] Scalable coding refers to dividing the code in terms of time, space, and quality to output multiple layers of bitstream (including a base layer and enhancement layers). The base layer data allows the decoder to decode the basic video content perfectly, but the resulting video image may have a lower frame rate, lower resolution, or lower quality. In situations with limited or complex channel / network conditions, the base layer data ensures that the decoder receives a smooth, viewable video image. When the channel / network environment is good or resources are abundant, enhancement layer data can be transmitted to improve the frame rate, resolution, or video quality.

[0142] For example, scalable coding refers to scaled video coding (SVC) technology, which can segment audio and video into multiple layers of data with different resolutions, qualities, and frame rates.

[0143] In this embodiment of the application, the base layer data includes: data obtained by encoding important information (or bits) in the audio and video, and the audio and video decoded based on the base layer data has the lowest image resolution and frame rate of the audio and video before encoding.

[0144] In tape region 1, the basic layer data is sequentially arranged on a finite length of tape 210. Thus, when the basic layer data is read by the read / write head, the head only needs to align with the target address within the corresponding finite length of tape region 1. This reduces the head's seek time and the number of contacts between the head and other tape regions, reducing wear on tape 210 and extending its lifespan. Furthermore, the basic layer data is smaller than the audio / video data, which reduces the long-tail latency of writing data to the magneto disk 200 when decoding audio / video based on the basic layer data for clients or video management platforms to obtain smooth audio / video.

[0145] In one alternative implementation, the scalable coding is executed by the processor 240 within the magnetoelectric disk 200.

[0146] In another alternative implementation, the scalable coding is performed by a controller externally connected to the magneto-electric disk 200, such as controller 1, control unit 1225 or other processing devices in Figure 1 above.

[0147] The two optional implementation methods described above are merely optional execution entities for the scalable coding provided in this application embodiment and should not be construed as limiting this application. For example, the magneto-electric disk 200 may be equipped with a separate codec chip, which is used to encode audio and video, or to decode data stored in the magnetic tape 210, etc.

[0148] S530: Write the audio / video enhancement layer data to tape area 2 of tape 210.

[0149] Among them, the enhancement layer data is obtained by processing the audio and video based on the base layer data. The quality of the audio and video obtained based on the base layer data and the enhancement layer data is higher than that obtained based on the base layer data.

[0150] In scalable coding scenarios, enhancement layer data depends on base layer data for decoding.

[0151] In one optional scenario, the enhancement layer data is obtained by performing inter-frame prediction on the audio and video based on the base layer data. Inter-frame prediction refers to prediction performed on a per-block basis, utilizing the correlation between the current frame and its reference frames (such as the image frames indicated by the base layer data). The current frame may have one or more reference frames. Specifically, a prediction block for the current image block is generated based on the pixels in the reference frames of the current image block. Depending on the prediction direction, inter-frame prediction includes forward prediction, backward prediction, and bidirectional prediction.

[0152] In another optional scenario, the enhancement layer data is obtained by performing intra-prediction on the audio and video based on the base layer data. Intra-prediction refers to predicting the pixel values ​​of pixels within the current image patch using the pixel values ​​of pixels within the reconstructed image patch located in the current image patch.

[0153] For further details on the implementation of inter-frame prediction and intra-frame prediction in the two optional scenarios mentioned above, please refer to the description of common techniques, which will not be elaborated here. Generally speaking, the amount of enhancement layer data obtained by intra-frame prediction is greater than that obtained by inter-frame prediction. However, the amount of enhancement layer data may vary depending on the specific implementation of inter-frame prediction and intra-frame prediction, and this application does not limit this.

[0154] In the first optional scenario, the storage capacity of one sub-wrap in the M sub-wraps (M=9) of tape region 1 is less than the storage capacity of one sub-wrap in the N sub-wraps (N=9) of tape region 2. As shown in Figure 5, the storage capacity of a single sub-wrap in tape region 1 (such as any one of sw1-1 to sw9-1) is less than the storage capacity of a single sub-wrap in tape region 2 (such as any one of sw1-2 to sw9-2). For example, the storage capacity of sw1-1 is 1MB, and the storage capacity of sw1-2 is 1.2MB.

[0155] In the second optional scenario, the storage capacity of one sub-wrap in the M sub-wraps (M=9) of tape region 1 is the same as the storage capacity of one sub-wrap in the N sub-wraps (N=9) of tape region 2. As shown in Figure 6, Figure 6 is a schematic diagram of the three data arrangements provided in this application. In Figure 6 (1), the storage capacity of a single sub-wrap in tape region 1 (such as any one of sw1-1 to sw9-1) is the same as the storage capacity of a single sub-wrap in tape region 2 (such as any one of sw1-2 to sw9-2), such as a sub-wrap with a storage capacity of 1MB.

[0156] In the third alternative scenario, the storage capacity of one sub-wrap in the M sub-wraps (M=9) of tape region 1 is greater than the storage capacity of one sub-wrap in the N sub-wraps (N=9) of tape region 2. In Figure 6(2), the storage capacity of a single sub-wrap in tape region 1 (such as any one of sw1-1 to sw9-1) is greater than the storage capacity of a single sub-wrap in tape region 2 (such as any one of sw1-2 to sw9-2), for example, the storage capacity of sw1-1 is 2MB and the storage capacity of sw1-2 is 1MB.

[0157] In the fourth optional scenario, the storage capacity of each sub-wrap in tape region 1 and tape region 2 differs. In Figure 6(3), the storage capacity of tape region 1 is less than that of tape region 2, and in wrap1, wrap2, wrap4, wrap5, wrap6, wrap8, and wrap9, the storage capacity of the sub-wrap in tape region 1 is less than that of the sub-wrap in tape region 2; in wrap3, the storage capacity of the sub-wrap in tape region 1 is equal to that of the sub-wrap in tape region 2; and in wrap7, the storage capacity of the sub-wrap in tape region 1 is greater than that of the sub-wrap in tape region 2.

[0158] Depending on the amount of data, the storage capacity of each sub-wrap in the tape area where the basic layer data and the enhanced layer data are located varies, and this application does not limit this.

[0159] As can be seen from the embodiments provided in Figures 5 and 6 above, the magneto-electric disk can store the basic layer data and enhancement layer data obtained by scalable encoding of audio and video separately, such as storing the data of different layers separately along the length of the magnetic tape into a finite length area of ​​the magnetic tape, with the magnetic tape area being longitudinally distributed within the finite length of the magnetic tape.

[0160] During audio and video access, the magneto-electric disk prioritizes reading the base layer data, and since the base layer data is relatively small, it can reduce the long-tail latency of the magneto-electric disk. Moreover, because the base layer data is distributed vertically within a finite length of magnetic tape area, the head seek time is reduced, further reducing the long-tail latency of the audio and video access process and improving the access efficiency of audio and video.

[0161] Several optional examples are provided below regarding the specific implementation methods of the enhancement layer data.

[0162] In the first optional example, the enhancement layer data includes: spatial enhancement layer data. Spatial enhancement layer data refers to data used to improve the resolution of audio and video obtained based on the base layer data. Optimizing the audio and video corresponding to the base layer data based on the spatial enhancement layer data results in higher resolution audio and video.

[0163] In the second optional example, the enhancement layer data includes temporal enhancement layer data. Temporal enhancement layer data refers to data used to improve the frame rate of audio and video obtained based on the base layer data. Optimizing the audio and video corresponding to the base layer data based on the temporal enhancement layer data results in a higher frame rate for the audio and video.

[0164] In a third optional example, the enhancement layer data includes quality enhancement layer data. Quality enhancement layer data refers to data used to improve the texture information of audio and video obtained based on the base layer data. Optimizing the audio and video corresponding to the base layer data based on the quality enhancement layer data results in audio and video with more texture information. Alternatively, the quality enhancement layer data can also be distinguished by a quantization parameter (QP). A larger QP indicates lower audio and video quality, while a smaller QP indicates higher audio and video quality. In this embodiment, the QP corresponding to the quality enhancement layer data is smaller than the QP corresponding to the base layer data, resulting in higher audio and video quality when optimizing the audio and video corresponding to the base layer data based on the quality enhancement layer data.

[0165] In the fourth optional example, the enhancement layer data includes: spatial enhancement layer data and temporal enhancement layer data.

[0166] In the fifth optional example, the enhancement layer data includes: spatial enhancement layer data and quality enhancement layer data.

[0167] In the sixth optional example, the enhancement layer data includes: temporal enhancement layer data and quality enhancement layer data.

[0168] In the seventh optional example, the enhancement layer data includes: spatial enhancement layer data, temporal enhancement layer data, and quality enhancement layer data.

[0169] The above seven optional examples are merely optional methods for enhancement layer data provided in the embodiments of this application, and should not be construed as limiting this application.

[0170] In the embodiments of this application, any one of the enhancement layer data, such as spatial enhancement layer data, temporal enhancement layer data, or quality enhancement layer data, can perform quality enhancement processing on the audio and video corresponding to the basic layer data to improve the audio and video quality of the audio and video corresponding to the basic layer data, such as resolution, frame rate, texture information, or QP, thereby improving the audio and video playback effect of the client.

[0171] The following description uses the seventh optional example to illustrate S530 above, as shown in Figure 7, which is a flowchart illustrating a data writing method provided in this application. In Figure 7, the magnetic tape 210 includes multiple tape regions arranged side-by-side along the length of the tape 210, such as tape region 1 (first tape region), tape region 2 (second tape region), tape region 3 (third tape region), and tape region 4 (fourth tape region). Referring to Figure 7, S530 above includes S531 to S533 below.

[0172] S531. Write the spatial enhancement layer data of the audio and video to tape area 2 of tape 210.

[0173] For example, the resolution of audio / video 2 (a single-frame pattern with denser pixels) corresponding to the spatial enhancement layer data is higher than the resolution of audio / video 1 (a single-frame pattern with sparser pixels) corresponding to the basic layer data. The specific implementation of the spatial enhancement layer data can be found in the description of S530 above, and will not be repeated here.

[0174] S532. Write the temporal enhancement layer data of the audio and video to tape area 3 of tape 210.

[0175] For example, the resolution of audio / video 3 (a multi-frame pattern with dense pixels) corresponding to the temporal enhancement layer data is higher than the frame rate of audio / video 2 (a single-frame pattern with dense pixels) corresponding to the spatial enhancement layer data. The specific implementation of the temporal enhancement layer data can be found in the description of S530 above, and will not be repeated here.

[0176] S533, Write the audio / video quality enhancement layer data to tape area 4 of tape 210.

[0177] For example, the resolution of the quality enhancement layer data corresponding to audio / video 4 (a multi-frame pattern with dense pixels and diagonal lines) is richer than the texture information of the temporal enhancement layer data corresponding to audio / video 3 (a multi-frame pattern with dense pixels). The specific implementation of the quality enhancement layer data can be found in the description of S530 above, and will not be repeated here.

[0178] Based on the above S531 to S533, it can be seen that the magneto-electric disk 200 stores different enhancement layer data of audio and video into different tape regions of the magnetic tape 210, so that the enhancement layer data belonging to the same tape region are arranged sequentially along the finite length of the magnetic tape 210, which helps to reduce the write latency of audio and video data and extend the service life of the magnetic tape 210.

[0179] It is worth noting that the data arrangement of different enhancement layer data in magnetic tape 210 provided in Figure 7 is only an optional method provided by the embodiments of this application. In other optional implementations, the data arrangement of different enhancement layer data in magnetic tape 210 may also be in other ways.

[0180] In the first possible approach, tape region 2 is used to store spatial enhancement layer data, tape region 3 is used to store quality enhancement layer data, and tape region 4 is used to store temporal enhancement layer data.

[0181] In the second possible approach, tape region 2 is used to store temporal enhancement layer data, tape region 3 is used to store spatial enhancement layer data, and tape region 4 is used to store quality enhancement layer data.

[0182] In the third possible approach, tape region 2 is used to store temporal enhancement layer data, tape region 3 is used to store quality enhancement layer data, and tape region 4 is used to store spatial enhancement layer data.

[0183] In the fourth possible approach, tape region 2 is used to store quality enhancement layer data, tape region 3 is used to store quality enhancement layer data, and tape region 4 is used to store spatial enhancement layer data.

[0184] In the fifth possible approach, tape region 2 is used to store quality enhancement layer data, tape region 3 is used to store spatial enhancement layer data, and tape region 4 is used to store temporal enhancement layer data.

[0185] The above, combined with Figure 7 and five possible methods, provides six possible data arrangement schemes, exemplifying the arrangement of enhancement layer data on magnetic tape 210. However, this should not be construed as limiting this application. In other optional implementations, tape region 1 can also be used to store enhancement layer data, and any one of tape regions 2 to 4 can be used to store basic layer data. That is to say, this application does not limit the specific tape region on tape 210 where different layers of audio and video data are stored. By arranging and combining different layers of data with different tape regions in tape 210, more data arrangement schemes can be provided, which will not be elaborated here.

[0186] In this embodiment, different enhancement layer data are stored in different tape regions of the magnetic tape. The different tape regions are arranged sequentially along the finite length of the tape, and different sub-wraps within the same tape region are distributed longitudinally along the width direction of the tape. When reading and writing enhancement layer data, the magnetic head only needs to move within the finite length of the tape body corresponding to that tape region, which reduces the addressing distance and addressing time of the magnetic head, thereby reducing the access latency and long tail latency of audio and video, which is beneficial to extending the service life of the magnetic tape 210.

[0187] The above description, in conjunction with Figures 5 and 7, illustrates the writing process of basic layer data and enhancement layer data. To further reduce the long-tail latency of writing data in tape 210, the following description, using multi-copy storage as an example, illustrates the data writing method provided in this application embodiment.

[0188] In the first alternative implementation, the base layer data, enhancement layer data, and copies of the audio and video are stored on the same tape.

[0189] As shown in Figure 8, Figure 8 is a flowchart of a data writing method provided in this application. In Figure 8, each magnetic tape region is arranged side by side along the length of the magnetic tape 210, such as magnetic tape region 1, magnetic tape region 2, magnetic tape region 5 and magnetic tape region 6 arranged side by side along the length of the magnetic tape 210.

[0190] Tape region 5 includes multiple sub-wraps, such as sw1-5 to sw9-5. In Figure 8, sw1-5 to sw9-5 come from different wraps in tape 210. Tape region 6 includes multiple sub-wraps, such as sw1-6 to sw9-6. In Figure 8, sw1-6 to sw9-65 come from different wraps in tape 210. Further arrangements of tape regions 5 and 6 can be found in the description related to Figure 6 above, and will not be repeated here. Referring to Figure 8, after S530 described above, the data writing method provided in this embodiment further includes the following S540 and S550.

[0191] S540, magneto disk 200 writes the first copy of the basic layer data to tape area 5 of tape 210.

[0192] The first copy is identical to the content of the base layer data. Referring to the various devices included in the magnetoelectric disk 200 in Figure 2, S540 is illustrated by way of example. The processor 240 in the magnetoelectric disk 200 sends a control command to the tape drive 220, which drives the reel 201 to wind up the tape, causing the magnetic head 230 to align with the tape region 5 in the tape 210. The magnetic head 230 then writes the first copy into the tape region 5 through magnetic changes.

[0193] S550, magneto disk 200 writes a second copy of the enhancement layer data to tape area 6 of tape 210.

[0194] The second copy is identical to the data in the enhancement layer. Referring to the various components included in the magnetoelectric disk 200 in Figure 2, S550 is illustrated by way of example. The processor 240 in the magnetoelectric disk 200 sends a control command to the tape drive 220, which drives the reel 201 to wind up the tape, causing the magnetic head 230 to align with the tape region 6 in the tape 210. The magnetic head 230 then writes the second copy into the tape region 6 through magnetic changes.

[0195] As can be seen from the embodiment provided in Figure 8, the magneto-electric disk uses a multi-copy redundant storage strategy to store multi-layer data of audio and video, so that the multi-layer data and its copies are stored in different tape areas of the magnetic tape, and the different tape areas are arranged side by side along the length of the tape, so that the magnetic head can more smoothly address the basic layer data on the tape, thereby reducing the access latency of audio and video, and further reducing the long tail latency of the audio and video access process, and improving the access efficiency of audio and video.

[0196] It is worth noting that the execution order of S540 and S550 can be concurrent with the aforementioned S520 and S530, or it can be executed sequentially after the aforementioned S520 and S530 have been completed. This application does not limit this.

[0197] In the second optional implementation, the basic layer data, enhancement layer data, and copies of the audio and video are stored on different magnetic tapes. Figure 9 is a flowchart illustrating a data writing method provided in this application. In Figure 9, magnetic tape 210 is also referred to as the first magnetic tape, and magnetic tape 211 is also referred to as the second magnetic tape; this application does not limit these terms.

[0198] In an alternative scenario, magnetic tape 210 and magnetic tape 211 are located on the same magnetoelectric disk, such as magnetoelectric disk 200 as described above.

[0199] In another alternative scenario, magnetic tape 210 and magnetic tape 211 are located on different magneto-electric disks, such as magnetic tape 210 being located on magneto-electric disk 200 and magnetic tape 211 being located on another magneto-electric disk.

[0200] The above two optional scenarios are merely optional methods for the first magnetic tape (magnetic tape 210) and the second magnetic tape (magnetic tape 211) provided in the embodiments of this application, and should not be construed as limiting this application.

[0201] In Figure 9, the magnetic tape 211 includes multiple wraps arranged side-by-side along the width direction of the tape, such as wraps 11 to wraps 19. The magnetic tape 211 also includes multiple tape regions arranged side-by-side along the length direction of the tape, such as tape region 7 and tape region 8.

[0202] Tape area 7 includes multiple sub-wraps, such as sw11-7 to sw19-7, which come from different wraps.

[0203] Tape area 8 includes multiple sub-wraps, such as sw11-8 to sw19-8, which come from different wraps.

[0204] Tape regions 7 and 8 may include more or fewer sub-wraps, which is not limited in this application.

[0205] Please refer to Figure 9. After S530 described above, the data writing method provided in this application embodiment also includes S560 and S570 below.

[0206] S560, Write the third copy of the basic layer data to tape area 7 of tape 211.

[0207] The third copy is identical to the content of the base layer data. For example, the processor sends a control command to the tape drive, which drives the spool to wind up the tape, aligns the read / write head with the tape region 7 in the tape 211, and writes the third copy into the tape region 7 by magnetic changes.

[0208] S570: Write the fourth copy of the enhancement layer data to tape area 8 of tape 211.

[0209] The fourth copy is identical to the content of the enhancement layer data. For example, the processor sends a control command to the tape drive, which drives the spool to wind up the tape, aligns the read / write head with the tape region 8 in the tape 211, and writes the fourth copy into the tape region 8 by magnetic changes.

[0210] As can be seen from the embodiment provided in Figure 9, the magneto-electric disk uses a multi-copy redundant storage strategy to store multi-layer data of audio and video. This allows the multi-layer data and its copies to be stored in different tape regions of different magnetic tapes. Furthermore, the different tape regions containing multi-layer data in the same magnetic tape are arranged side by side along the length of the tape. This enables the magnetic head to address the basic layer data more smoothly on the magnetic tape, thereby reducing the access latency of audio and video and further reducing the long-tail latency of the audio and video access process, thus improving the access efficiency of audio and video.

[0211] It is worth noting that the execution order of S560 and S570 can be concurrent with the aforementioned S520 and S530, or it can be executed sequentially after the aforementioned S520 and S530 have been completed. This application does not limit this.

[0212] The first optional scenario: When tape 210 is not accessed, head 1 is located in tape region 1. Head 1, also called the first head, is positioned in tape region 1 where the basic layer data is located. During audio / video access, the addressing distance of the first head (head 1) is reduced, which helps to reduce the head's addressing time, thereby reducing the long-tail latency of the audio / video access process and improving audio / video access efficiency. Referring to Figure 2, this head 1 is the head 230 provided in the aforementioned embodiment.

[0213] The second optional scenario: When tape 211 is not accessed, head 2 is located in tape region 5. Head 2, also called the second head, is positioned in tape region 5 where the basic layer data is located. During audio / video access, the addressing distance of the second head (head 2) is reduced, which helps to reduce the addressing time of the second head, thereby shortening the long-tail latency of the audio / video access process and improving the efficiency of audio / video access. When tape 210 and tape 211 belong to the same magneto-electric disk, head 1 and head 2 can be the same head, such as head 230 provided in the aforementioned embodiment.

[0214] The third optional scenario: As shown in Figure 9, when tape 210 is not accessed, head 1 is located in tape region 1, and when tape 211 is not accessed, head 2 is located in tape region 5. Each head is located in the tape region containing the basic layer data of its corresponding tape. During audio / video access, the head closest to the target address can be selected to read the basic layer data of the audio / video, further reducing the head's addressing distance and addressing time, and shortening the long-tail latency of the audio / video access process. When tapes 210 and 211 belong to different magneto-electric disks, head 1 can be head 230 provided in the aforementioned embodiment, and head 2 can be a head from another magneto-electric disk.

[0215] Figures 5 to 9 above illustrate the data writing method provided in the embodiments of this application. The following, in conjunction with Figures 6, 7, and 9, further describes the magnetic tape data arrangement implemented by the data writing method provided in the embodiments of this application, as shown in Figure 10. Figure 10 is a schematic diagram of a data arrangement structure provided in this application. In Figure 10, the magnetic tape region 9 in the magnetic tape 211 includes multiple sub-wraps, such as sw11-9 to sw19-9, which come from different wrappers. The magnetic tape region 10 in the magnetic tape 211 includes multiple sub-wraps, such as sw11-10 to sw19-10, which come from different wrappers. For a description of other hardware in Figure 10, please refer to the description of the foregoing embodiments; it will not be repeated here.

[0216] In Figure 10, tape region 1 and tape region 7 are used to store the same basic layer data, tape region 2 and tape region 8 are used to store the same spatial enhancement layer data, tape region 3 and tape region 9 are used to store the same temporal enhancement layer data, and tape region 4 and tape region 10 are used to store the same quality enhancement layer data.

[0217] In different magnetic tapes, the size of the tape area used to store the same layer of data can be the same, such as tape area 1 and tape area 7; the size of the tape area used to store the same layer of data can also be different, such as tape area 2 and tape area 8.

[0218] Figure 10 illustrates the example of copies being stored on different magnetic tapes. Multi-layer data can also be stored in different areas of the same magnetic tape, which will not be elaborated here.

[0219] As shown in the embodiment provided in Figure 10, by scalably encoding audio / video / images to obtain layered data (different layers of data correspond to different information in the audio / video / image, and superimposing them yields the audio / video / image), and by using IO scheduling or other methods to sequentially write different layers of data onto the magnetic tape and vertically arrange the data of the same layer on the finite length of the tape, it is beneficial to reduce the addressing latency of data reading and writing. Storing different layers of data using a multi-copy strategy helps to reduce access latency in random read / write scenarios and improve the access efficiency of audio / video.

[0220] With different layers of audio and video data already written to the magnetic tape, the data reading method provided by the embodiments of this application will be described exemplarily below with reference to the accompanying drawings. Figure 11 is a schematic flowchart of a data reading method provided by this application. For a description of the hardware in Figure 11, please refer to the description of the foregoing embodiments; it will not be repeated here. Referring to Figure 11, the data reading method provided by the embodiments of this application includes the following steps S1110 to S1150.

[0221] S1110, The client sends a read request to the magneto disk 200.

[0222] Correspondingly, the magneto disk 200 receives read requests from the client.

[0223] The read request includes the identifier of the target audio or video.

[0224] For example, the identifier could be a timestamp of the target audio / video. Or, for example, it could be tagging or annotation information for the target audio / video. Or, for example, it could be a global identifier for the target audio / video, used to uniquely identify its content.

[0225] The above are merely optional methods of identification provided in the embodiments of this application and should not be construed as limiting this application.

[0226] S1120, magneto disk 200 responds to a read request and reads the basic layer data of the target audio / video from tape area 1 of tape 210 according to the identifier of the target audio / video.

[0227] S1120 is illustrated by way of example with reference to the magnetoelectric disk 200 provided in Figure 2. The processor 240 in the magnetoelectric disk 200 sends a control command to the tape drive 220, which drives the reel 201 to wind the tape, so that the magnetic head 230 is aligned with the tape region 1 in the tape 210, and the magnetic head 230 reads the basic layer data stored in the tape region 1 by means of magnetic changes.

[0228] S1130 and magneto disk 200 send the basic layer data of the target audio and video to the client.

[0229] Correspondingly, the client receives the basic layer data of the target audio and video sent by the magneto disk 200, and parses the basic layer data to obtain smooth audio and video.

[0230] Based on the content of S1110 to S1130, it can be seen that the different magnetic tape areas arranged side by side along the length of the magnetic tape in the magneto-electric disk are used to store different layers of audio and video data. Since the magnetic tape areas are distributed longitudinally within a finite length of magnetic tape, the magneto-electric disk prioritizes reading the basic layer data during audio and video access. Moreover, the amount of basic layer data is relatively small, which can reduce the long-tail latency of the magneto-electric disk.

[0231] Moreover, since the basic layer data is distributed longitudinally within a finite length of magnetic tape area, the head addressing time is reduced, further reducing the long-tail latency of the audio and video access process, which is beneficial to improving the access efficiency of audio and video.

[0232] Optionally, please continue to refer to Figure 11. After S1110 above, the data reading method provided in this application embodiment also includes S1140 and S1150 below.

[0233] S1140, magneto disk 200 pre-fetches the enhancement layer data of the target audio and video stored in tape area 2 of tape 210 into cache 241 according to the identifier of the target audio and video.

[0234] In this embodiment of the application, the read / write speed of the cache 241 is greater than that of the magnetic tape 210.

[0235] For example, the processor 240 in the magneto disk 200 sends a control command to the tape drive 220, which drives the reel 201 to wind the tape, so that the magnetic head 230 aligns with the tape region 2 in the tape 210, and the magnetic head 230 reads the enhancement layer data stored in the tape region 2 by magnetic changes, and writes the enhancement layer data into the cache 241.

[0236] As an optional implementation, the process by which the magneto-electric disk 200 prefetches enhancement layer data from tape region 2 into cache 241 includes: obtaining prefetch description information, and writing the target enhancement layer data stored in the second tape region of the tape into the cache according to the prefetch description information.

[0237] In the first optional example, the prefetch description information includes: the client's transmission bandwidth. Transmission bandwidth refers to the amount of data that can be transmitted between the client and the magneto disk 200 per unit time, such as 100MB or 1000MB.

[0238] In the second alternative example, the prefetch description information includes: target resolution.

[0239] In the third alternative example, the prefetch description information includes: the client's transmission bandwidth and target resolution.

[0240] In the embodiments of this application, the aforementioned prefetch description information is also referred to as user equipment conditions or access environment, etc., and this application does not limit it to these terms.

[0241] The target enhancement layer data includes one or a combination of the following: spatial domain enhancement layer data of the target audio / video, temporal domain enhancement layer data of the target audio / video, and quality enhancement layer data of the target audio / video. The specific implementation methods of each enhancement layer data can be referred to the description in the foregoing embodiments, and will not be repeated here.

[0242] In other words, the magneto disk 200, in conjunction with the client's device conditions (such as transmission bandwidth and target resolution), prefetches enhancement layer data that matches the client's device conditions into the cache, provided that the client has already obtained the basic layer data of the audio and video. Since the read and write speed of the cache is greater than that of the magnetic tape, the data transmission efficiency between the cache and the client is improved while the amount of enhancement layer data remains unchanged. The access latency and long-tail latency of audio and video transmission are reduced, which is conducive to improving the access efficiency of audio and video.

[0243] Optionally, please continue to refer to Figure 11. The data reading method provided in this application embodiment also includes the following S1150.

[0244] S1150 and magneto disk 200 send the cached enhancement layer data to the client.

[0245] Correspondingly, the client receives the enhancement layer data of the target audio and video sent by the magneto disk 200, and optimizes the quality of the smooth audio and video based on the enhancement layer data corresponding to the aforementioned basic layer data, thereby improving the user's viewing experience.

[0246] Based on the content of S1110 to S1150, it can be seen that during the transmission of basic layer data, the magneto-electric disk also prefetches enhancement layer data into the cache for backup. Since the read and write speed of the cache is greater than that of the magnetic tape, it ensures that when the client receives the basic layer data, it can play audio and video smoothly based on the basic layer data, and can also improve the audio and video quality by using the enhancement layer data prefetched in the cache.

[0247] The data reading method provided in this application embodiment can also be adjusted according to different layers of data and multiple replica strategies during the data writing process. More details about different layers of data and multiple replica strategies can be found in the descriptions of Figures 6 to 10 above, and will not be repeated here.

[0248] In summary, when data has scalable or incremental coding characteristics, the short longitudinal addressing latency of magnetic tape can be used to arrange data from different layers longitudinally on a finite length tape to reduce addressing latency.

[0249] Optionally, the magneto-electric disk 200 may also include a sensor and a safety module. The sensor can be used to determine the relative position between the magnetic tape and the magnetic head, and the safety module is used to encrypt the data stored in the magneto-electric disk 200, etc. The sensor and the safety module can also be electrically connected to the controller via a management bus, which is not limited in this application.

[0250] This application also provides a storage system. The storage system includes a communication interface, a controller, and a magnetoelectric disk as provided in any of the foregoing embodiments. The magnetoelectric disk is used to store data, the communication interface is used to receive data access requests, and the controller is used to manage target magnetoelectric disks in the storage system according to data access requests. The storage system may be, for example, a magnetic tape library, or a computer / server containing a magnetic tape drive as a persistent storage medium, such as the storage system 120 or disk drive 122 provided in FIG. 1.

[0251] The controller includes one or more processors, which can be a very large-scale integrated circuit. The processor contains an operating system and other software programs, enabling it to access tape drives and various PCIe devices. The processor includes one or more processor cores. These cores can be, for example, a central processing unit (CPU) or other ASICs. The processor can also be other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. In practical applications, the storage system may also include multiple controllers.

[0252] Optionally, the storage system may also include, but is not limited to, other storage media: dynamic random access memory (DRAM), static random access memory (SRAM), etc., for caching data from the tape drive for processor processing. Additionally, other storage media may be read-only memory (ROM). For example, read-only memory may be programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), etc. This embodiment does not limit the number or type of other storage media. Furthermore, other storage media can be configured to have power-saving functionality. Power-saving functionality means that when the system experiences a power outage and is then powered on again, the data stored in the memory will not be lost. Storage media with power-saving functionality are called non-volatile memory.

[0253] Furthermore, in the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video disc (DVD); or it can be a semiconductor medium, such as a solid-state drive (SSD).

[0254] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Various equivalent modifications or substitutions can be conceived within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for writing data, characterized in that, The method includes: Acquire audio and video data; the audio and video data includes video data and / or audio data. Write the basic layer data of the audio and video into the first tape area of ​​the first tape. The basic layer data is obtained by scalable encoding of the audio and video. The first tape includes multiple wraps, where each wrap includes K sub-wraps. The first tape area includes M sub-wraps, and the M sub-wraps come from different wraps, where K≥2 and M≥2. The audio / video enhancement layer data is written into the second tape area of ​​the first tape. The enhancement layer data is obtained by processing the audio and video based on the base layer data. The quality of the audio and video obtained based on the base layer data and the enhancement layer data is higher than that obtained based on the base layer data. The first tape region and the second tape region are arranged side by side along the length of the first tape. The second tape region includes N sub-wraps, which come from different wraps, and N≥2.

2. The method according to claim 1, characterized in that, The storage capacity of one of the M sub-wraps may be the same as or different from the storage capacity of one of the N sub-wraps.

3. The method according to claim 1 or 2, characterized in that, The method further includes: Write a copy of the basic layer data to the third tape area; Write a copy of the enhancement layer data to the fourth tape region; Wherein, the first magnetic tape region, the third magnetic tape region, and the fourth magnetic tape region are arranged side by side along the length direction of the first magnetic tape; or, the third magnetic tape region and the fourth magnetic tape region are arranged side by side along the length direction of the second magnetic tape.

4. The method according to claim 3, characterized in that, When the first magnetic tape is not accessed, the first magnetic head is located in the first magnetic tape area; And / or, if the second magnetic tape is not accessed, the second magnetic head is located in the third magnetic tape area.

5. The method according to any one of claims 1-4, characterized in that, The enhancement layer data includes one or a combination of the following: spatial enhancement layer data, temporal enhancement layer data, and quality enhancement layer data.

6. A method for reading data, characterized in that, The method includes: Obtain the client's read request; the read request includes the identifier of the target audio / video; In response to the read request, the target audio / video base layer data is read from the first tape region of the tape according to the identifier; The magnetic tape includes multiple wraps, and each wrap includes K sub-wraps, where K ≥ 2. The first magnetic tape region includes M sub-wraps, which come from different wraps, where M ≥ 2. The target audio and video are scalably encoded to obtain the base layer data and enhancement layer data. The enhancement layer data is stored in a second magnetic tape region arranged parallel to the first magnetic tape region along the length of the magnetic tape. The second magnetic tape region includes N sub-wraps, where N ≥ 2. The quality of the audio and video obtained based on the base layer data and the enhancement layer data is higher than the quality of the audio and video obtained based on the base layer data. Send the basic layer data of the target audio and video to the client.

7. The method according to claim 6, characterized in that, After obtaining the client's read request, the method further includes: The enhancement layer data of the target audio and video stored in the second tape region of the magnetic tape is pre-fetched into the cache; the read / write speed of the cache is greater than that of the magnetic tape. The enhancement layer data in the cache is sent to the client.

8. The method according to claim 7, characterized in that, The step of pre-fetching the enhancement layer data of the target audio / video stored in the second tape region of the magnetic tape into the cache includes: Obtain prefetch description information; the prefetch description information includes: the client's transmission bandwidth and / or target resolution; According to the prefetch description information, the target enhancement layer data stored in the second tape region of the tape is written into the cache; wherein, the target enhancement layer data includes one or more of the following combinations: spatial domain enhancement layer data of the target audio and video, temporal domain enhancement layer data of the target audio and video, and quality enhancement layer data of the target audio and video.

9. The method according to any one of claims 6-8, characterized in that, The storage capacity of one of the M sub-wraps may be the same as or different from the storage capacity of one of the N sub-wraps.

10. A magnetic tape, characterized in that, include: Multiple tape regions; The plurality of magnetic tape regions include: a first magnetic tape region and a second magnetic tape region arranged side by side along the length direction of the magnetic tape; The magnetic tape includes multiple wraps, where each wrap includes K sub-wraps, K≥2; The first tape area includes M sub-wraps, which are derived from different wraps, where M ≥ 2. The first tape area is used to store the basic layer data of the target audio and video; the basic layer data of the target audio and video is obtained by scalable encoding of the target audio and video. The second tape area includes N sub-wraps, which are from different wraps, and N≥2. The second tape area is used to store the enhancement layer data of the target audio-visual content. The enhancement layer data of the target audio-visual content is obtained by processing the target audio-visual content based on the base layer data. The quality of the audio-visual content obtained based on the base layer data and the enhancement layer data is higher than the quality of the audio-visual content obtained based on the base layer data.

11. The magnetic tape according to claim 10, characterized in that, The storage capacity of one of the M sub-wraps may be the same as or different from the storage capacity of one of the N sub-wraps.

12. The magnetic tape according to claim 10 or 11, characterized in that, The plurality of magnetic tape regions further includes: a third magnetic tape region and a fourth magnetic tape region arranged side by side with the first magnetic tape region along the length direction of the magnetic tape; The third tape region is used to store a copy of the base layer data, and the third tape region includes multiple sub-wraps from different wraps in the first tape; The fourth tape region is used to store a copy of the enhancement layer data, and the fourth tape region includes multiple sub-wraps from different wraps in the first tape.

13. A magnetoelectric disk, characterized in that, include: A communication interface for acquiring audio and video data; the audio and video data includes one or both of video data and audio data. A magnetic tape includes multiple magnetic tape regions, wherein the multiple magnetic tape regions include a first magnetic tape region and a second magnetic tape region arranged side by side along the length direction of the magnetic tape; The magnetic tape has multiple wraps, where each wrap contains K sub-wraps, and K ≥ 2; The first tape region includes M sub-wraps, wherein the M sub-wraps come from different wraps, and M ≥ 2; The second tape region includes N sub-wraps, which are derived from different wraps, where N ≥ 2; A magnetic head, used to access the magnetic tape; A processor for cooperating with the audio / video and the magnetic head to perform the method of any one of claims 1-9.

14. A storage system, characterized in that, include: A controller; one or more magnetoelectric disks as described in claim 13; The controller is used to acquire audio and video, and to perform the method of any one of claims 1-9 in coordination with the audio and video and the magneto-electric disk.

15. A computer program product, characterized in that, When the computer program product is run in an electronic device, the electronic device performs the method of any one of claims 1-9.

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