A hard disk testing method, device, computer equipment and storage medium

Abstract

The application relates to the technical field of testing, and particularly discloses a hard disk testing method and device, computer equipment and a storage medium, the method comprises the following steps: controlling a first port and a second port of a dual-port solid state disk to execute a load test, and executing a power-off operation and a power-on operation on the first port and the second port; after the power-off operation and the power-on operation are executed on the first port and the second port, detecting whether the states of the first port and the second port are normal and whether test basic information is normal; in response to the states of the first port and the second port being normal and the test basic information being normal, returning to the step of controlling the first port and the second port of the dual-port solid state disk to execute the load test; and in response to the state of the first port or the second port being abnormal or the test basic information being abnormal, collecting dual-port solid state disk test information. Through the scheme, the stability test after power-off and power-on is realized, and the test efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of testing technology, and in particular to a hard disk testing method, apparatus, computer equipment, and storage medium. Background Technology

[0002] In active-active or redundant link modes, the power-on / off and driver loading processes of dual-port SSDs are more complex than those of single-port SSDs. During power-on, scenarios may occur where both ports load drivers simultaneously. The context request for driver loading sent by the Product Manager (PM) needs to be processed in the Computing Manager (CM). Subsequent driver loading can only proceed after power-on is complete. During the power-off process, one port of a dual-port SSD needs to check if the other port is in a normal state. The complex power-on / off and driver loading processes of dual-port SSDs place higher demands on disk stability and present more complex scenarios. Current SSD power-on / off stability testing methods have the following problems: they are only applicable to ordinary single-port SSDs and servers, and can only operate on a single port, failing to meet the complex scenarios of simultaneous driver loading / unloading on both ports or simultaneous relatively independent load testing on both ports; manual disk removal testing cannot fully cover the power-on / off processes during test execution, wasting manpower and time and resulting in insufficient test coverage, failing to cover complex test scenarios and the power-on / off driver loading process. Summary of the Invention

[0003] In view of this, the present invention proposes a hard disk testing method, apparatus, computer equipment, and storage medium, which improves the coverage of power-on and power-off stability testing of dual-port solid-state drives in dual-active mode; and covers test scenarios where both ports of a dual-port solid-state drive simultaneously load and unload drivers and both ports simultaneously send loads; it can realize automated testing without the need for manual plugging and unplugging of solid-state drives, saving manpower and improving testing efficiency.

[0004] To achieve the above objectives, one aspect of the present invention provides a hard disk testing method, specifically including the following steps performed by a control device:

[0005] The first and second ports of the dual-port solid-state drive are controlled to perform load tests, and power-down and power-on operations are performed on the first and second ports.

[0006] After performing power-down and power-on operations on the first port and the second port, check whether the status of the first port and the second port is normal and whether the basic information is normal.

[0007] In response to the normal status of the first port and the second port and the normal test basic information, return to the step of controlling the first port and the second port of the dual-port solid-state drive to perform load test;

[0008] If the status of the first port or the second port is abnormal, or if the basic test information is abnormal, the test information of the dual-port solid-state drive is collected.

[0009] In some implementations, the test equipment includes a dual-port server and the dual-port solid-state drive, wherein the dual-port solid-state drive is connected to the dual-port server, and the dual-port server is connected to the control device via a relay.

[0010] In some embodiments, the power-down operation includes:

[0011] Perform a shutdown or restart on the first port and the second port respectively to de-energize the first port and the second port; or

[0012] The control relay disconnects the power supply to the dual-port solid-state drive and the dual-port server, thereby powering down the dual-port solid-state drive and the dual-port server.

[0013] In some implementations, the power-on operation includes:

[0014] The control relay connects the power supply to the dual-port server, thereby powering on the dual-port solid-state drive and the dual-port server.

[0015] In some implementations, the load test includes:

[0016] Based on the test load, read and write operations were performed on the first port and the second port respectively.

[0017] In some implementations, controlling the first and second ports of the dual-port solid-state drive to perform load tests includes:

[0018] The Security Enclosure Protocol controls the first and second ports of the dual-port solid-state drive to perform load tests.

[0019] Another aspect of this invention provides a hard disk testing method, comprising:

[0020] The dual-port server is connected to the control device via a relay, and a dual-port solid-state drive is inserted into the dual-port server. The control device then performs the following steps:

[0021] The first and second ports of the dual-port solid-state drive are controlled to perform load tests, and power-down and power-on operations are performed on the first and second ports.

[0022] After performing power-down and power-on operations on the first port and the second port, check whether the status of the first port and the second port is normal and whether the basic information is normal.

[0023] In response to the normal status of the first port and the second port and the normal test basic information, return to the step of controlling the first port and the second port of the dual-port solid-state drive to perform load test;

[0024] If the status of the first port or the second port is abnormal, or if the basic test information is abnormal, the test information of the dual-port solid-state drive is collected.

[0025] In another aspect of this invention, a hard disk testing apparatus is provided, applied to a control device, the apparatus comprising:

[0026] The control module is configured to control the first and second ports of the dual-port solid-state drive to perform load tests, and to perform power-down and power-on operations on the first and second ports.

[0027] The detection module is configured to detect whether the status of the first port and the second port is normal and whether the basic information is normal after performing power-down and power-on operations on the first port and the second port.

[0028] The return module is configured to return a step to control the first and second ports of the dual-port solid-state drive to perform a load test in response to the normal status of the first port and the second port and the normal test basic information.

[0029] The collection module is configured to collect the dual-port solid-state drive test information in response to an abnormal state of the first port or the second port, or an abnormal test basic information.

[0030] In another aspect of the present invention, a computer device is provided, comprising: at least one processor; and a memory storing a computer program executable on the processor, the computer program performing the steps of the method described above when executed by the processor.

[0031] In another aspect, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method steps.

[0032] The present invention has at least the following beneficial technical effects: the solution of the present invention improves the coverage of power-on and power-off stability testing of dual-port solid-state drives in dual-active mode; and covers the test scenario of loading and unloading drivers on both ports of the dual-port solid-state drive at the same time and sending loads on both ports at the same time; it can realize automated testing without the need to manually plug and unplug the solid-state drive, saving manpower and improving testing efficiency. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0034] Figure 1 A block diagram of an embodiment of the hard disk testing method provided by the present invention;

[0035] Figure 2 A schematic diagram of an embodiment of the hard disk testing device provided by the present invention;

[0036] Figure 3 A schematic diagram of the structure of an embodiment of the computer device provided by the present invention;

[0037] Figure 4 This is a schematic diagram of an embodiment of the computer-readable storage medium provided by the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0039] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0040] Based on the above objectives, a first aspect of the present invention provides an embodiment of a hard disk testing method. For example... Figure 1 As shown, the method includes performing the following steps based on the control device:

[0041] S10. Control the first and second ports of the dual-port solid-state drive to perform load tests, and perform power-down and power-on operations on the first and second ports;

[0042] S20. After performing power-down and power-on operations on the first port and the second port, check whether the status of the first port and the second port is normal and whether the basic information is normal.

[0043] S30. In response to the normal status of the first port and the second port and the normal test basic information, return to the step of controlling the first port and the second port of the dual-port solid-state drive to perform load test;

[0044] S40. In response to an abnormal state of the first port or the second port, or an abnormal test basic information, the test information of the dual-port solid-state drive is collected.

[0045] Specifically, a dual-port solid-state drive (SSD) is a drive connected to two different storage controllers. Depending on the application scenario, it can be configured in active-active, master-slave, or link redundancy modes. This allows the other controller to still access the drive even if the link between one storage controller and the drive fails, thereby improving the high availability of the storage system and ensuring business continuity.

[0046] The control device can be a desktop computer, laptop computer, or similar device. The control device controls the first port A and the second port B of the dual-port SSD to perform load tests, simultaneously powering on and off both ports A and B. It checks the network status of ports A and B to ensure they are functioning correctly and that the dual-port SSD is recognized. It also checks the basic test information. If everything is normal, the above operations are repeated. If any information is abnormal, such as a ping failure on either port or a disk malfunction on either port, the test is stopped, and information about the dual-port SSD is collected to locate and troubleshoot the problem.

[0047] The present invention improves the coverage of power-on and power-off stability testing for dual-port solid-state drives in dual-active mode; it also covers test scenarios where both ports of a dual-port solid-state drive send loads simultaneously; it enables automated testing; and it eliminates the need for manual plugging and unplugging of the solid-state drive, saving manpower and improving testing efficiency.

[0048] In some implementations, the test equipment includes a dual-port server and the dual-port solid-state drive, wherein the dual-port solid-state drive is connected to the dual-port server, and the dual-port server is connected to the control device via a relay.

[0049] In one specific embodiment, the basic test information includes dual-port server information and test information. Detecting whether the basic test information is normal may specifically include: checking whether the dual-port server has started successfully, whether the dual-port solid-state drives are properly positioned on both ports of the dual-port server, whether the drivers for the dual-port solid-state drives on both ports of the dual-port server have been properly loaded, whether the link speed of the dual-port server has been reduced or the LAN (local area network) has been reduced, and executing power-on / off scenarios, the number of power-on / off cycles, etc.

[0050] In some embodiments, the power-down operation includes:

[0051] Perform a shutdown or restart on the first port and the second port respectively to de-energize the first port and the second port; or

[0052] The control relay disconnects the power supply to the dual-port solid-state drive and the dual-port server, thereby powering down the dual-port solid-state drive and the dual-port server.

[0053] In one specific embodiment, the power-down operation is divided into normal power-down and abnormal power-down. Normal power-down refers to powering down the dual-port SSD, while abnormal power-down refers to powering down the dual-port server power supply while the dual-port SSD is working normally. Normal power-down includes shutdown and restart. If the dual-port SSD is being shut down, the dual-port server power supply is powered down after the dual-port SSD is shut down. After completing the above power-down operation, the dual-port server power supply is then turned on to power on the dual-port SSD. If the dual-port SSD is being restarted, no power-on operation is required after the dual-port SSD is shut down; the system simply waits for the system to restart.

[0054] Specifically, `init0` (shutdown) or `reboot` (restart) is executed on port A and port B of the dual-port SSD to achieve normal power-down of the dual-port SSD through ports A and B. An abnormal power-down is achieved by controlling a relay to open via a control device, disconnecting the power to both the dual-port server and the dual-port SSD, thus achieving abnormal power-down of ports A and B. The power-down method can be freely selected according to testing requirements; a single fixed method or a random method can be chosen.

[0055] It should be noted that if init0 is used to power down the first port A and the second port B, then after powering down the first port A and the second port B, the control relay needs to be turned on to disconnect the power supply to the dual-port server and the dual-port SSD, so that the dual-port SSD can be powered down normally through the first port A and the second port B.

[0056] In some implementations, the power-on operation includes:

[0057] The control relay connects the power supply to the dual-port server, thereby powering on the dual-port solid-state drive and the dual-port server.

[0058] In one specific embodiment, after the dual-port solid-state drive is powered down normally by executing init 0 or abnormally by disconnecting the power supply, the power supply to the disk and the machine is connected by controlling the relay through the control device to complete the power-on operation.

[0059] After powering down and then powering on, check if the network status of port A and port B is normal, and whether the dual-port SSD can be recognized normally on port A and port B. Also check if the basic test information is normal. If all are normal, repeat the above operation. If any information is abnormal, stop the test, collect the dual-port SSD information to locate the problem and troubleshoot the cause.

[0060] In some implementations, the load test includes:

[0061] Based on the test load, read and write operations were performed on the first port and the second port respectively.

[0062] In one specific embodiment, a workload is randomly selected, and read and write operations are performed simultaneously on the first port A and the second port B of the dual-port solid-state drive. The read and write operations include any of the following: random read, random write, sequential read, sequential write, mixed read and write, fiotrim (format), reset, read and write with verification, and no load.

[0063] In some implementations, controlling the first and second ports of the dual-port solid-state drive to perform load tests includes:

[0064] The Security Enclosure Protocol controls the first and second ports of the dual-port solid-state drive to perform load tests.

[0065] The control device remotely controls the first port A and the second port B of the dual-port SSD via SSHpass (a command based on the Secure Shell protocol) to perform load tests. Simultaneously, it performs power-down and power-on operations on both ports A and B. The device checks the network status of ports A and B to ensure they are functioning correctly and that the dual-port SSD is recognized. It also checks the basic test information. If everything is normal, the above operations are repeated. If any information is abnormal, such as a ping failure on either port or a disk malfunction on either port, the test is stopped, and information about the dual-port SSD is collected to locate and troubleshoot the problem.

[0066] Based on the same inventive concept, according to another aspect of the present invention, embodiments of the present invention also provide a hard disk testing method, comprising:

[0067] The dual-port server is connected to the control device via a relay, and a dual-port solid-state drive is inserted into the dual-port server. The control device then performs the following steps:

[0068] The first and second ports of the dual-port solid-state drive are controlled to perform load tests, and power-down and power-on operations are performed on the first and second ports.

[0069] After performing power-down and power-on operations on the first port and the second port, check whether the status of the first port and the second port is normal and whether the basic information is normal.

[0070] In response to the normal status of the first port and the second port and the normal test basic information, return to the step of controlling the first port and the second port of the dual-port solid-state drive to perform load test;

[0071] If the status of the first port or the second port is abnormal, or if the basic test information is abnormal, the test information of the dual-port solid-state drive is collected.

[0072] Specifically, the dual-port server and the control unit are connected via a relay. The dual-port solid-state drive is inserted into the dual-port server slot. Each port of the dual-port server is assigned two IP addresses for subsequent control devices to remotely control the dual-port solid-state drive.

[0073] The control device remotely controls the first port A and the second port B of the dual-port SSD via SSHpass (a command based on the Secure Shell protocol) to perform load tests. Simultaneously, it performs power-down and power-on operations on both ports A and B. The device checks the network status of ports A and B to ensure they are functioning correctly and that the dual-port SSD is recognized. It also checks the basic test information. If everything is normal, the above operations are repeated. If any information is abnormal, such as a ping failure on either port or a disk malfunction on either port, the test is stopped, and information about the dual-port SSD is collected to locate and troubleshoot the problem.

[0074] The present invention improves the coverage of power-on and power-off stability testing for dual-port solid-state drives in dual-active mode; it also covers test scenarios where both ports of a dual-port solid-state drive send loads simultaneously; and it enables automated testing without the need for manual plugging and unplugging of the solid-state drive, saving manpower and improving testing efficiency.

[0075] Based on the same inventive concept, according to another aspect of the present invention, such as Figure 2 As shown, embodiments of the present invention also provide a hard disk testing apparatus, applied to a control device, the apparatus comprising:

[0076] The control module 110 is configured to control the first port and the second port of the dual-port solid-state drive to perform load testing, and to perform power-down and power-on operations on the first port and the second port.

[0077] The detection module 120 is configured to detect whether the status of the first port and the second port is normal and whether the basic information is normal after performing power-down and power-on operations on the first port and the second port.

[0078] Return module 130 is configured to return the steps of controlling the first port and the second port of the dual-port solid-state drive to perform load testing in response to the normal status of the first port and the second port and the normal test basic information.

[0079] The collection module 140 is configured to collect the dual-port solid-state drive test information in response to an abnormal state of the first port or the second port, or an abnormal test basic information.

[0080] The various exemplary logic blocks, modules, and circuits described herein can be implemented or performed using the following components designed to perform the functions herein: general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of these components. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP, and / or any other such configuration.

[0081] The steps of the methods or algorithms described herein can be directly incorporated into hardware, into a software module executed by a processor, or a combination of both. The software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from or write information to the storage medium. In an alternative, the storage medium can be integrated with the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In an alternative, the processor and storage medium can reside as discrete components in the user terminal.

[0082] Based on the same inventive concept, according to another aspect of the present invention, such as Figure 3As shown, an embodiment of the present invention also provides a computer device 30, which includes a processor 310 and a memory 320. The memory 320 stores a computer program 321 that can be run on the processor. When the processor 310 executes the program, it performs the steps of the method described above.

[0083] The memory, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the hard disk testing method described in the embodiments of this application. The processor executes various system functions and data processing by running the non-volatile software programs, instructions, and modules stored in the memory, thereby implementing the hard disk testing method described in the above embodiments.

[0084] The memory may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on system usage. Furthermore, the memory may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the local module via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0085] Based on the same inventive concept, according to another aspect of the present invention, such as Figure 4 As shown, embodiments of the present invention also provide a computer-readable storage medium 40, which stores a computer program 410 that, when executed by a processor, performs the methods described above.

[0086] Finally, it should be noted that those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The storage medium for the program can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. The above computer program embodiments can achieve the same or similar effects as any of the corresponding foregoing method embodiments.

[0087] Those skilled in the art will also understand that the various exemplary logic blocks, modules, circuits, and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the functionality of various illustrative components, blocks, modules, circuits, and steps has been generally described. Whether this functionality is implemented as software or as hardware depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art can implement the functionality in various ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the embodiments disclosed herein.

[0088] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. The sequence numbers of the disclosed embodiments of this invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0089] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0090] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A hard disk testing method, characterized in that, The following steps are performed based on the control device: The system controls the first and second ports of the dual-port solid-state drive (SSD) to simultaneously perform load tests. The load test involves performing at least one of the following operations on the first and second ports based on a test load: random read, random write, sequential read, sequential write, mixed read / write, and read / write with verification. Simultaneously, power-down and power-on operations are performed on the first port A and the second port B. These power-down and power-on operations include: shutting down or restarting the first port A and the second port B of the dual-port SSD to achieve normal power-down of the SSD through the first port A and the second port B, or controlling a relay to open via a control device to disconnect the power supply to the dual-port server and the dual-port SSD to achieve abnormal power-down of the first port A and the second port B; after performing normal power-down or abnormal power-down on the dual-port SSD, the control device controls a relay to connect the disk and the machine's power supply to complete the power-on operation. After performing power-down and power-on operations on the first port and the second port, check whether the network status of the first port and the second port is normal, whether the dual-port solid-state drive can be recognized normally on the first port A and the second port B, check whether the dual-port server has started successfully, whether the dual-port solid-state drive is in place normally on both ports of the dual-port server, whether the driver of the dual-port solid-state drive on both ports of the dual-port server has been loaded normally, whether the link speed of the dual-port server has been reduced, and whether the power-on and power-off scenarios and the number of power-on and power-off cycles are normal. In response to the normal status of the first port and the second port and the normal test basic information, return the step of controlling the first port and the second port of the dual-port solid-state drive to perform load test simultaneously; If the status of the first port or the second port is abnormal, or if the basic test information is abnormal, the test information of the dual-port solid-state drive is collected to locate the cause of the fault.

2. The method according to claim 1, characterized in that, The test equipment includes a dual-port server and the dual-port solid-state drive, wherein the dual-port solid-state drive is connected to the dual-port server, and the dual-port server is connected to the control device via a relay.

3. The method according to claim 1, characterized in that, Controlling the first and second ports of the dual-port SSD to perform load tests includes: The Security Enclosure Protocol controls the first and second ports of the dual-port solid-state drive to perform load tests.

4. A hard disk testing device, characterized in that, Applied to control equipment, the device includes: The control module is configured to control the first and second ports of the dual-port solid-state drive (SSD) to simultaneously perform load testing. The load testing involves performing at least one of the following operations on the first and second ports based on a test load: random read, random write, sequential read, sequential write, mixed read / write, and read / write with verification. Simultaneously, power-down and power-on operations are performed on the first port A and the second port B. These power-down and power-on operations include: shutting down or restarting the first port A and the second port B of the dual-port SSD to achieve normal power-down of the SSD through the first port A and the second port B, or controlling a relay to open via a control device to disconnect the power supply to the dual-port server and the dual-port SSD to achieve abnormal power-down of the first port A and the second port B; after performing normal power-down or abnormal power-down on the dual-port SSD, controlling a relay via a control device to connect the disk and the machine power supply to complete the power-on operation. The detection module is configured to, after performing power-down and power-on operations on the first port and the second port, detect whether the network status of the first port and the second port is normal, whether the dual-port solid-state drive can be correctly recognized on the first port A and the second port B, check whether the dual-port server has started successfully, whether the dual-port solid-state drive is in place on both ports of the dual-port server, whether the driver for the dual-port solid-state drive on both ports of the dual-port server has been loaded normally, whether the link speed of the dual-port server has been reduced, and whether the power-on and power-off scenarios and the number of power-on and power-off cycles are normal. The return module is configured to return a step to control the first and second ports of the dual-port solid-state drive to perform load testing simultaneously in response to the normal status of the first port and the second port and the normal test basic information. The collection module is configured to collect the test information of the dual-port solid-state drive in response to an abnormal state of the first port or the second port, or an abnormal test basic information, in order to locate the cause of the fault.

5. A computer device, comprising: At least one processor; as well as A memory storing a computer program executable on the processor, characterized in that the processor executes the program by performing the steps of the method as described in any one of claims 1 to 3.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it performs the steps of the method as described in any one of claims 1 to 3.

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