233 results about "Sequential access" patented technology

A scalable content delivery network (SCDN) employs a parallel download mechanism to ensure that a demanded file is present at a station in time for user consumption. This mechanism is used in solving the content caching and storage problem for applications such as video-on-demand, which is commonly perceived as a tough problem in the industry. In the network, files are divided into smaller units called tracks according to the nature of data contained in each of them. Tracks are further divided into smaller equally sized units called block files. This division builds the foundation for parallel download. A sequence server provides a lock-free mechanism for multiple threads or processes to access data atomically. The sequence server allows clients to gain sequential access to data, or to find out whether the sequence has been violated so that they can retry their operation or take corrective action. Advantages of the invention include the ability to handle distribution of large files and process sequencing.

Digital data records are stored on a direct access storage device (DASD) in emulation of sequential-access media, the efficiency of storage and access of the data being improved by using a volume trailer containing various statistics about the records. Data is preferably stored in records, logically assembled into record groups. Interspersed with the records, there may be one or more marker codes, which function like tape marks among the various data records. The volume trailer contains pointers to each record group, record counts for each group, marker code counts for each group, and may also include fields showing whether records in a given record group are of equal length. The volume trailer may also include a volume trailer "tail", including a byte count for the entire volume trailer, and a unique sequence identifying the volume trailer. Statistics contained in the volume trailer enable substantially more efficient access of the data by a DASD. For example, record groupings, group counts, and/or marker code counts may be employed to perform operations such as locate, forward space file, and backward space file.

A portion of digital data records are stored on a direct access storage device (DASD) in emulation of sequential-access media when the parent digital data records are transferred to a sequential-access media. The efficiency of storage and access to the data portion is improved by random-access recall of the data in the data portion, and by constructing a data portion trailer containing various statistics about the records for referencing the digital data and advancing to target data. The volume data portion trailer is constructed as read forward and forward space block operations are performed. Data is preferably stored in logically assembled records. Interspersed with the records, there may be one or more marker codes, which function like tape marks among the various data records. The volume trailer may contain pointers to each record, a record count and marker codes for the data portion. Statistics contained in the data portion trailer enable substantially more efficient access of the data by a DASD.

Disclosed is a system for caching data. After determining a sequential access of a first memory area, such as a direct access storage device (DASD), a processing unit stages a group of data sets from the first memory area to a second memory, such as cache. The processing unit processes a data access request (DAR) for data sets in the first memory area that are included in the sequential access and reads the requested data sets from the second memory area. The processing unit determines trigger data set from a plurality of trigger data sets based on a trigger data set criteria. The processing unit then stages a next group of data sets from the first memory area to the second memory area in response to reading the determined trigger data set.

A method for navigating within a multi-level hierarchical collapsing menu structure is disclosed. Each level in the menu structure contains plural items, each item being at least one of a function, a pointer to a location, and a pointer to another level. The method of the present invention includes a step of providing a graphical user menu system displaying the items of a given level and enabling selection thereof, wherein access of the given level requires sequential access of each of the levels preceding the given level in the hierarchy. An Active Path is dynamically constructed as a sequence of active links as items are selected using the graphical user menu system, with one active link correspond to each of the items selected. The active links provide direct access to a function corresponding level or menu item without the need to navigate using the graphical user menu system.

Embodiments of the present invention provide mechanisms for improving storage consumption on a sequential access medium, such as a physical tape, by preferably storing one instance of a data block of a backup data set on the tape media. When another instance of a data block is received having the same pattern as the stored data block, rather than storing the data block itself, a reference to the data block is stored on the sequential access medium. When data are restored, data blocks are cached at a block store on a storage device(s) having a faster seek time than the tape. When a reference to a previously stored data block is read from the tape, rather than re-winding the tape to search for the data block on the tape (which might take a long time to locate), the referenced data block can be found on the storage device having a faster seek time than the tape media.

In an ink jet printer of the present invention, in order to reduce the manufacturing cost, an inexpensive EEPROM enabling only sequential accesses is applied for storage elements incorporated in a black ink cartridge and a color ink cartridge. The data array of a memory cell included in each of the storage elements mounted on the ink cartridges is determined in such a manner that a second storage area, in which rewritable data, for example, data on remaining quantities of inks in the ink cartridge, are stored, is accessed prior to a first storage area, in which read only data are stored. This configuration enables the rewritable data to be securely written into the second storage area even after a power-off operation. The second storage area has two memory divisions allocated to each ink, that is, a first ink remaining quantity memory division and a second ink remaining quantity memory division. Latest data on the remaining quantity of each ink is alternately written into these two memory divisions. Alternatively, the latest data on the remaining quantity of each ink is written into these two memory divisions in a duplicated manner. Each ink remaining quantity memory division has a write complete flag to determine whether or not a writing operation has been completed normally in the ink remaining quantity memory division. This arrangement enables the remaining quantities of the respective inks to be monitored accurately and continuously.

A method and system for improving performance with single-instance-storage volumes by leveraging data locality is provided. A client provides a set of fingerprints generated from data segments to be saved to a single-instance storage volume and receives the information on whether a data segment exists on the single-instance storage volume and where it is stored if a data segment exists. Based on its received information, the client determines if a number of non-sequential accesses of a computer-readable medium for the set of segments from the single-instance-storage volume exceeds a predetermined threshold. If so, the client provides the whole set of data segments for storage within the single-instance storage volume regardless of whether or not the data segments are duplicate data segments. These sent data segments will be stored contiguously within the single-instance storage volume while the duplicates will be removed from their previous stored locations.

A method and system that combines efficient caching and buffering to provide a network file system, that may utilize data stored in one or more compressed image files of sequentially arranged byte stream data. As an application requests file opens and file reads of a file system, one or more drivers convert the block requests into HTTP: byte range requests or the like in order to retrieve the data from a remote server. As the data is received, it is reconverted and adjusted to match the application's request. Sequential block access patterns can be detected and used to request additional data in a single request, in anticipation of future block requests, thereby increasing efficiency. Local caching of received data, including caching after uncompressing received data that was compressed, further increases efficiency. A compressed file system format optimized for sequential access is also described that when used, further improves the efficient data access.

To prevent random access commands from remaining even in the case of mixed sequential and random accesses. A storage medium control unit is used in a data storage device adapted to perform processing on a data storage medium based on multiple requests including sequential access requests and random access requests. The storage medium control unit includes: request response delay monitoring device for monitoring the presence of delay in response to the requests based on whether or not the response time for each request exceeds a certain allowable delay time; and request control device for preventing the rearrangement processing of the sequential access requests and controlling the processing of the requests to be performed in a certain request order at the allowable delay time if exceeded.

The invention is directed to a method of transmitting a file having an advertising portion and a requested portion different from the advertising portion. The method includes receiving a request to transmit the file, via a streaming protocol allowing non-sequential access, transmitting the advertising portion of the file, receiving a request to transmit a portion of the requested portion of the file prior to completing transmitting the advertising portion of the file, completing the transmission of the advertising portion of the file, and transmitting the requested portion of the file.

In a printer of the present invention, an EEPROM that carries out sequential access and has a relatively small storage capacity is applied for storage elements mounted on both black and color ink cartridges, which are detachably attached to the printer. Pieces of information relating to each ink cartridge, for example, pieces of information on remaining quantities of respective inks in the ink cartridge, are stored in the storage element of the ink cartridge. A format of addressing adopted in the storage elements of the ink cartridges is different from that adopted in an EEPROM Incorporated in a printer main body of the printer. A control IC provided in the printer accordingly converts the storage format of addressing, before writing the information into the storage elements of the ink cartridges. In the printer, a RAM is mounted with the control IC on a carriage, and the pieces of information to be written into the storage elements of the ink cartridges are temporarily registered in the RAM. The pieces of information are then written into the respective storage elements of the black and color ink cartridges, for example, at a timing of a power-off operation. The signal lines and the memory used in the course of writing the information into the storage elements are identical with the signal lines, through which print data are transmitted to a print head mounted on the carriage of the printer, and the memory, in which the print data are stored. The arrangement of the present invention reduces the manufacturing cost of the ink cartridge and also enables size reduction of the whole printer.

The invention discloses a mixed storage system and a storage method based on solid state disks and magnetic hard disks. The mixed storage system is characterized by comprising an array consisting of one or a plurality of magnetic hard disks, an array consisting of one or a plurality of solid hard disks and a storage controller, wherein the magnetic hard disk array and the solid state disk array are connected with a computer bus through the storage controller. The storage controller maintains a mapping table from logic pages to physical pages, and is in charge of counting access modes of the logic pages at the same time. According to the performance characteristics of the solid state disks and the magnetic hard disks, the pages are optimally distributed so that hotspot pages which is fewer and is random accessed more are distributed to the solid state disk array, and most common pages with fewer access or mainly based on sequential access are distributed in the magnetic hard disk array, thereby fully exerting the performance superiority of high speed random access of the solid state disks, improving the access performance of the whole system and shortening the time of searching and responding.

Storage drive logic and a standalone tape file structure are described. File transfer logic transfers file data to and from a network according to a first protocol. Media access logic accesses a sequential-access storage medium associated with the drive according to a second protocol. Media management logic translates file-based commands received from the network according to the first protocol into sequential-access device commands according to the second protocol. The device commands control accessing of data by the drive. The storage medium may be a magnetic tape including a data region for storing data in a file format, and a table of contents (TOC) region for storing a table of contents that indexes the locations of files within the data region.

An ordered semaphore management subsystem and method for use in an application system which includes a plurality of processors competing for shared resources each of which is controlled by a unique semaphore. The subsystem generates an ordered semaphore field (OSF) corresponding to each processor in a linked list of processors and assigns one of four statuses to the OSF depending on the position the processor occupies in the linked list of processors competing for the shared resources. The four states are (1) semaphore head (SH); (2) behind semaphore head (BSH); (3) semaphore head behind (SHB); and (4) skip (Skip). Only the SH processor is allocated the semaphore when requested. A processor not in the SH state will be denied the semaphore even if is available to assure sequential access.

A container is configured to provide sequential access to contents therein, and includes an upper portion and a lower portion connected to the upper portion by a hinged portion, the lower portion defining an interior space bearing a moveable tray and an opening through which the moveable tray may move, the moveable tray defining an interior volume configured to receive at least one device therewithin. The container also includes at least one device borne by the moveable tray, at least one cavity for receiving the at least one device disposed in the upper portion and at least one insert located between the upper and lower portions, the at least one insert comprising at least written indicia thereon.