JPH08190462A - Disk array device - Google Patents

Abstract

PURPOSE: To lighten the operation load at the time of the rewriting of firmware by providing a detachable hard disk on which a control program is stored, and reading the control program out of the hard disk and writing it in a memory by a control means when a disk array device is started. CONSTITUTION: The firmware is stored on the hard disk 3a as one of hard disks that can easily be mounted on and demounted from the main body of the disk array device 1 and when the device is powered on, this firmware is read out of the hard disk 3a and written in the RAM 5. If the firmware needs to be rewritten like a case wherein new firmware is offered by the maker of the disk array device 1, only the hard disk 3a on which the firmware is only mounted is detached and replaced with a hard disk on which the new firmware is mounted, so the operation for firmware replacement is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk array device connected to a computer or the like and used as a storage device for storing data.

[0002]

2. Description of the Related Art Heretofore, a disk array device as described below has been known as one of storage devices used by being connected to a computer such as a host computer, a workstation or a personal computer.

The disk array device is provided with a plurality of hard disks, and divides data instructed to be written by a computer into a predetermined unit length such as a byte unit or a sector unit, and divides the divided data into a plurality of pieces. It is configured to write to the hard disk in parallel. Further, since the error correction code for each data is generated and stored together with the data itself, it is possible to read and write the data normally based on the error correction code even if a part of the hard disk fails. The advantage is that the life of data as a whole and the reliability of data are improved.

Incidentally, the data division and the error correction as described above are carried out by a DP which will be described later and which is provided in the disk array device.
Since it is performed by C (Data Path Controller), data writing and reading can be performed from the computer side without being aware of a plurality of hard disks, as if using one hard disk.

Here, the schematic configuration of the above-mentioned conventional disk array device will be described with reference to FIG. As shown in the figure, the conventional disk array device 1 is connected to a computer 2 such as a personal computer, a workstation or a host computer, and writes and reads data according to the instructions of the computer 2. , A disk array 3 composed of a plurality of hard disks, and a ROM (Read Onl
y Memory) 4 ', RAM (Random Access Memory) 5,
CPU (Central Processing Unit) 6 and DPC
And a substrate 8 on which 7 is mounted.

The ROM 4'has firmware, which is a microprogram for controlling the operation of the disk array apparatus 1, and is read from the ROM 4'when the disk array apparatus 1 is powered on. It is output and written in RAM5, CPU6, R
The operation of the disk array device 1 is controlled based on the firmware on the AM 5.

Under the control of the CPU 6, the DPC 7 also performs a process of dividing data and writing the data in parallel to a plurality of hard disks, and a process of reading and integrating the data distributed in the plurality of disks. Further, when writing data, an error correction code is generated and the generated error correction code is written to the hard disk dedicated to the error correction code of the disk array 3. On the other hand, when reading the data, the error correction code of the data to be read is taken out from the hard disk dedicated to the error correction code and the error correction is performed.

As described above, in the conventional disk array device, by generating and storing the error correction code together with the data, for example, one of the plurality of hard disks fails and becomes inaccessible. Even if a part of the data cannot be read, the data to be read can be completed based on the error correction code.

[0009]

SUMMARY OF THE INVENTION In the above conventional configuration,
The firmware is mounted on the ROM 4 ′ mounted on the board 8 inside the apparatus main body. Since this ROM 4'is a non-rewritable memory, for example, firmware version upgrades to add or improve functions,
Alternatively, when the firmware is rewritten for various reasons such as dealing with a malfunction of the firmware, it is necessary to remove the ROM 4'and replace it with a ROM in which new firmware is installed.

However, it is generally difficult for the user to remove the ROM 4'or the substrate 8 on which the ROM 4'is mounted, and at the time of removing these, other parts are accidentally destroyed. Since it is feared that the disk array device will be lost, the fact is that the manufacturer of the disk array device collects and replaces the device body, which poses a problem that the work load is heavy.

Further, during this period, the user of the disk array device cannot use the device, which is inconvenient, and in some cases, business interruption may cause economic disadvantages. There is also the problem that there is.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a disk array device capable of reducing the work load when rewriting firmware and shortening the time required for the rewriting work. .

[0013]

In order to solve the above-mentioned problems, the disk array device of the present invention has a control means for controlling data write and data read operations based on a control program on a memory. The provided disk array device is characterized by including a removable hard disk in which the control program is stored, and the control means reads the control program from the hard disk and writes it in the memory when the device is activated.

[0014]

According to the above construction, when the apparatus is activated, the control program is read from the hard disk and written in the memory, and the control means writes the data and reads the data based on the control program on the memory. Control the behavior of. Since the hard disk is detachably attached to the main body of the apparatus, for example, when the control program is rewritten for reasons such as version upgrade of the control program, the hard disk is removed from the apparatus and a new control program is added. The rewriting work can be done by a simple procedure of installing the hard disk in which is stored instead.

As a result, the work load when the control program is rewritten can be reduced, the time required for the work can be shortened, and the user cannot use the disk array device for a long time, so that the user cannot use the disk array device for a long time. It is possible to avoid situations such as suffering a disadvantage.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS. As shown in FIG. 1, the disk array device 1 in this embodiment is connected to a computer 2 via a well-known interface such as SCSI or SCSI-2, and writes data according to the instruction of the computer 2. And read. The disk array device 1 includes a disk array 3 including hard disks 3a, 3b, 3c, 3d, 3e, a ROM (Read Only Memory) 4, and a RAM.
(Random Access Memory) 5, CPU as control means
(Central Processing Unit) 6 and DPC (Data
Path controller) 7 and a substrate 8 on which the path controller 7 is mounted.

As shown in FIG. 5, each of the above-mentioned hard disks 3a to 3e has a magnetic disk 11, a movable arm 13 having a magnetic head 12 at the tip thereof for randomly accessing the magnetic disk 11, and a movable arm. 1
A servo mechanism (not shown) for controlling the operation of No. 3 is housed in the cartridge 14. A card edge type connector 15 is provided on one of the side surfaces of the cartridge 14, and a connector on the receiving side provided in a slot of the disk array device 1 corresponding to the connector 15 is provided with the above-mentioned connector. The hard disk is mounted on the disk array device 1 by inserting and connecting the card edge of the connector 15. If you want to fix the hard disk more surely, the cartridge 14
It is also possible to provide a stopper or the like on the outer surface of the.

When the hard disk is removed from the disk array device 1, the cartridge 14 is pulled by hand and pulled out from the connector on the card edge receiving side of the connector 15 without using any special tool. It can be easily removed from the slot. The hard disk is a precision device such as a magnetic disk 11, a magnetic head 12, a movable arm 13,
Since the servo mechanism and the servo mechanism are housed inside the cartridge 14, they can be safely carried.

The hard disk 3a stores firmware (control program) which is a micro program for the CPU 6 to control the operation of each part of the disk array device 1. In the above configuration, when the disk array device 1 is powered on, the boot program loaded in the ROM 4 is written in the RAM 5.

The above boot program is used for the disk array 3
Is a program for controlling the CPU 6 to read the firmware from the hard disk 3 and write it to the RAM 5. Based on this startup program, the CPU 6 writes the firmware from the hard disk 3a of the disk array 3 as indicated by the solid arrow in FIG. Read and write to RAM5. After that, the CPU 6 controls the operations of the DPC 7 and the like according to the firmware written in the RAM 5.

Next, data writing and reading operations in the disk array device 1 will be described with reference to FIGS. 2, 3 (a) and 3 (b), and 4 (a) and 4 (b). FIG. 2 is a schematic diagram showing the flow of data instructed by the computer 2 for writing / reading, as indicated by arrows in the figure. As is clear from the figure, all of the above-mentioned data passes through the DPC 7, and is written or read in parallel to the hard disks 3a to 3e of the disk array 3 under the control of the DPC 7 based on the firmware.

Here, an outline of the data writing and reading processes will be described for the normal case and the disk array 3 abnormal case.

First, referring to FIG. 3A, a case where a computer 2 (not shown) instructs to write a character string "ABC" will be described as an example, and a data writing process in a normal state will be described. The above character string is DP
It is decomposed into three character strings of "A", "B" and "C" by C7. The decomposed character strings are respectively written in the same address in the hard disk 3a, the hard disk 3b and the hard disk 3c. Further, the hard disk 3d stores a parity generation code X for generating parity data as an error correction code, and the parity generation code X and the character string "ABC" are stored in the parity generation unit 9 of the DPC 7.
Parity data P is generated from the data and written to the hard disk 3e dedicated to the parity data.

Next, the case of reading the data written as described above will be described with reference to FIG. When the computer 2 issues an instruction to read data, the DPC 7 causes the hard disks 3a to 3
The character strings "A", "B", and "C" are read from the same address of c, and these are integrated to form the character string "ABC".
Generate Thereafter, the generated character string is output to the computer 2 to complete the data reading.

The above is the outline of the data writing and reading process under normal conditions. Next, as shown in FIG. 4A, the data writing process when the hard disk 3c fails, for example, will be described. To do. Similar to the process described above with reference to FIG.
7 divides the character string "ABC" into the character strings "A", "B" and "C", and tries to write to the hard disks 3a to 3c. However, since the hard disk 3c is inaccessible due to a failure, the character string "C" is not actually written. Similarly to the above, the parity data P is generated from the generation code X and the character string "ABC" in the parity generation unit 9 and written in the hard disk 3e. That is, the writing operation is completed in a state where the character string "A" is written in the hard disk 3a, the character string "B" is written in the hard disk 3b, and the parity data P is written in the hard disk 3e.

Further, when the data thus written is read out, as shown in FIG.
Reads the character string "A" from the hard disk 3a and the character string "B" from the hard disk 3b, and the hard disk 3c is in an inaccessible state. Therefore, the parity generation unit 9 determines that the character strings "A" and "B". , The generated code X read from the hard disk 3d and the hard disk 3
The character string "ABC" is restored based on the parity data P read from e. After that, the read operation is completed by outputting the restored character string to the computer 2.

As described above, since the disk array device 1 generates the parity data and stores it in the hard disks 3a to 3e together with the data itself, one of the hard disks 3a to 3c fails and becomes inaccessible. Even if it falls, you can read and write the correct data.

When a new firmware is provided by the manufacturer of the disk array device 1 by, for example, upgrading the firmware to add or improve a new function, the manufacturer writes the new firmware. Send the hard disk to the user,
The user easily rewrites the firmware by removing only the hard disk 3a storing the firmware from the slot of the apparatus main body and installing a hard disk in which new firmware is written instead. be able to.

Alternatively, the service engineer of the manufacturer may take the hard disk in which the new firmware is written to the user side and replace it with the hard disk in which the old firmware is installed.

As described above, in the configuration of this embodiment, the firmware is stored in the hard disk 3a, which is one of the hard disks that can be easily attached to and detached from the main body of the disk array device 1. This firmware is read from the hard disk 3a and written in the RAM 5 when the power of the device is turned on.

Therefore, when it becomes necessary to rewrite the firmware, such as when new firmware is provided by the manufacturer of the disk array device 1, only the hard disk 3a on which the firmware is installed is rewritten. Since it suffices to perform the work of removing and replacing the hard disk with new firmware installed, the work load required for replacing the firmware can be reduced, and the time during which the user cannot use the disk array device 1 can be shortened. There is an effect that becomes.

Although the present embodiment has been described by taking as an example the configuration in which five hard disks are used and parity data is used as the error correction code, the present invention is not limited to these, and the number of hard disks can be increased. Alternatively, the number of hard disks storing the error correction code can be set arbitrarily, and as the error correction code, for example, a Hamming code or the like can be used in addition to the above.

[0033]

As described above, the disk array device of the present invention includes the removable hard disk in which the control program is stored, and the control means reads the control program from the hard disk when the device is started. The configuration is such that writing is performed in the memory.

As a result, it becomes possible to reduce the work load when the control program is rewritten due to the version upgrade of the control program and the time required for the work can be shortened. This has the effect of avoiding a situation in which the array device cannot be used.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a disk array device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a data flow in the disk array device.

FIG. 3 is an explanatory diagram showing a normal data flow in the disk array device, wherein FIG. 3A shows data writing and FIG. 3B shows data reading.

FIG. 4 is an explanatory diagram showing a data flow when a hard disk fails in the disk array device, FIG. 4A shows data writing, and FIG. 4B shows data reading.

FIG. 5 is a partially cutaway perspective view showing a structure of a hard disk included in the disk array device.

FIG. 6 is a block diagram showing a schematic configuration of a conventional disk array device.

[Explanation of symbols]

 1 disk array device 2 computer 3 disk array 3a hard disk 4 ROM 5 RAM (memory) 6 CPU (control means) 7 DPC 8 substrate

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Claims (1)

[Claims] 1. A disk array device comprising control means for controlling data writing and data reading operations based on a control program on a memory, comprising a removable hard disk storing the control program. The disk array device, wherein the control means reads the control program from the hard disk and writes the control program in the memory when the device is activated.