JP2000298556A - Disk array device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a disk array having the same or almost the same capacity as that of all disk devices by using plural disk devices having respectively different capacity values. SOLUTION: A size calculation part 6 in a disk array controller 10 determines the greatest common measure of capacity values of plural real disk devices Disk1 to DiskN as the size of a virtual disk device. A control part 3 sets up individual divided areas obtained by dividing the disk areas of respective real disk devices Disk1 to DiskN by the size as virtual disk devices and constructs a disk array by using plural virtual disk devices including plural virtual disk devices generated on the same disk device. When read and write requests are outputted from a master device to the disk array, an address conversion part 4 refers to a disk constitution table and converts the addresses of the virtual disk devices into the addresses of the real disk devices.

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, and more particularly to a technique for constructing a disk array using disk devices having different capacities.

[0002]

2. Description of the Related Art A disk array device that stores data in a distributed manner on a plurality of disk devices depends on how the data is distributed and stored.
D5, etc., are all constructed using disk devices of the same capacity. It is possible to configure a disk array using disk devices of different capacities, but in such a case, no matter how large the capacity of each disk device, the disk with the smallest capacity of the disk array It was only used as the same capacity as the device, and the use efficiency of the disk capacity was significantly reduced.

In view of such circumstances, when a disk array is constructed using disk devices of different capacities, a technique for making it possible to use a disk area which could not be used as a conventional disk array in the disk array is disclosed in Japanese Patent Laid-Open Publication No. HEI 9 (1994). There is a technique described in JP-A-8-249132.
In this technology (hereinafter, referred to as a conventional technology), one disk array is configured using the disk area of the same capacity as the disk apparatus having the minimum capacity from the head of the disk area in each disk apparatus, and disks other than the minimum capacity are configured. The surplus disk area in the device is used for another disk array. For example, four 1 Gbyte disk units and 50
If there is one 0 Mbyte disk unit, 1G
A disk array of 500 M × 5 = 2.5 Gbytes is configured by using the first 500 Mbytes of the disk area of the 1-byte disk unit and the remaining 50 Mbytes of the 1 Gbyte disk unit.
500M × 4 = 2 using 0MB disk area
Configure another disk array of G bytes. A similar technique is described in JP-A-9-120342.

[0004]

According to the above-mentioned prior art, a disk area which cannot be used as a disk array in the past can be used for the disk array, and the use efficiency of the disk area can be improved. However, the maximum capacity of a single disk array that can be constructed is limited to “the minimum disk capacity × the number of disk devices”, and the largest feature of the disk array, that is, large capacity cannot be realized.

Accordingly, an object of the present invention is to make it possible to construct a disk array having a capacity equal to or nearly equal to the sum of the capacities of all the disk drives using disk drives of different capacities.

[0006]

According to the present invention, in order to achieve the above object, at least any two real disk devices having different capacities are divided into disk areas of the same capacity. Are used as virtual disk devices, and a disk array is configured using a plurality of virtual disk devices of the same capacity, including a plurality of virtual disk devices generated on the same real disk device. More specifically, in a disk array device including a plurality of real disk devices having different capacities of at least any two real disk devices and a control device connected to the plurality of real disk devices, The control device includes a size register that holds a size for dividing a disk area of the plurality of real disk devices, and a virtual disk device that defines individual disk regions obtained by dividing the plurality of real disk devices by the size. Means for generating a disk configuration table indicating the correspondence between the virtual disk device and the real disk device, and configuring a disk array using a plurality of virtual disk devices including a plurality of virtual disk devices generated on the same real disk device Means for reading and writing the disk configuration data when read and write requests are made to the disk array from a higher-level device. And means for converting the address for the actual disk device from the corresponding address for the virtual disk device with reference to the table.

According to the present invention, a disk array corresponding to RAID0 is configured using all generated virtual disk devices.

The present invention also provides a RAID1 using as many virtual disk devices as possible within a range satisfying a condition that a master virtual disk device and a slave virtual disk device do not exist on the same real disk device. Configure a corresponding disk array.

Further, according to the present invention, a virtual disk device in a real disk device with the smallest number of virtual disk devices generated is used as a parity disk, and a virtual disk device generated on another real disk device is used as a data disk. A disk array corresponding to RAID3 is configured by using these.

Further, the present invention further comprises means for calculating the greatest common divisor of the capacities of the plurality of real disk devices, and sets the value obtained by the means in the size register.

Further, the present invention further comprises a size setting register for holding a minimum size, and means for calculating the greatest common divisor of the capacities of the plurality of real disk devices, wherein the value obtained by the means is the minimum size. If smaller, the minimum size is set in the size register; otherwise, the determined value is set in the size register.

In the disk array device of the present invention,
When a plurality of real disk devices are divided into disk regions of the same capacity, each disk area is defined as a virtual disk device, and a plurality of virtual disks of the same capacity are included, including a plurality of virtual disk devices generated on the same real disk device. Since a disk array is configured using the devices, it is possible to construct a disk array having a capacity equal to or substantially equal to the sum of the capacities of all the disk devices.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a view for explaining the principle of an embodiment of the present invention. Now, consider a case where a disk array is constructed using two real disk devices D1 and D2 having different capacities as shown in FIG. Here, it is assumed that the capacity of the real disk device D1 is 1.5 times that of the real disk device D2. Conventionally, the entire disk area of the real disk device D2 having a small capacity and the disk area corresponding to the capacity of the real disk device D2 from the beginning of the real disk device D1 constitute one disk array. The remaining disk space was unused. JP-A-8-249
In Japanese Patent Publication No. 132, the remaining disk area of the unused actual disk device D1 is used as another disk array. Therefore, although the use efficiency of the disk area is improved, two disk arrays, that is, a disk array having twice the capacity of the real disk device D2 and a disk array having half the capacity of the real disk device D2, have been formed.

In the case of the present invention, as shown in FIG. 1B, the disk areas of the real disk devices D1 and D2 are divided by, for example, the greatest common divisor size of each capacity, and each of the divided areas is virtually divided. Disk devices D11 to D13, D21, D
22, the virtual disk devices D11 to D13,
One disk array is configured by treating each of D21 and D22 as one real disk device. As a result, the capacity of the disk array becomes equal to the sum of the capacities of the real disk devices D1 and D2, and a large-capacity disk array can be constructed. Hereinafter, examples of the embodiment of the present invention will be described.

[0016]

Referring to FIG. 2, an embodiment of a disk array apparatus according to the present invention includes a disk array controller (DAC) 10 connected to a CPU 1, which is a host apparatus, and an address line 12 and an address line 12 connected to the disk array controller 10. It is composed of a plurality of real disk devices Disk 1 to Disk N connected via the data line 13. Here, at least any two of the real disk devices Disk1 to DiskN have different capacities from each other.

The disk array controller 10
Includes a control unit 3, an interface 2 connected between the control unit 3 and the CPU 1, and a virtual disk configuration unit 11 connected to the control unit 3.

Further, the virtual disk configuration unit 11 includes an address conversion unit 4 and a size calculation unit 6 connected to the control unit 3.
And a size register 5 provided between the address conversion unit 4 and the size calculation unit 6. The address conversion unit 4 includes a disk configuration table 7.

Referring to FIG. 3, one embodiment of the control unit 3 includes an MPU 301 connected to the interface 2,
A RAM 303 for holding programs to be executed by the MPU 301 and various kinds of information, a cache 302 connected to the MPU 301, a selector 304, interfaces 306 and 307, and between the selector 304 and each of the real disk devices Disk1 to DiskN. The disk interfaces 305-1 to 305-N are connected to the address conversion unit 4 via the interface 306 and to the size calculation unit 6 via the interface 307, respectively.

FIG. 4 is a flowchart showing an example of a procedure for constructing a disk array using a plurality of real disk devices. First, a real disk device to be used for a disk array is determined (step S1). This is performed by the system administrator determining and notifying the MPU 301 in the control unit 3 of the disk array controller 10 via the CPU 1. When all of the real disk devices actually connected to the disk array controller 10 are used for the disk array, the MPU 301 is mounted on the real disk device via the selector 304 and the disk interfaces 305-1 to 305-N. Can be automatically determined by recognizing. Hereinafter, it is assumed that one disk array is constructed using all of the real disk devices Disk1 to DiskN.

Next, the number (ID) and the capacity of each real disk device used for the disk array are obtained and temporarily stored in the RAM 303 (step S2). This is because the MPU 301 of the control unit 3 controls each of the real disk devices Disk 1 to Disk
The number and capacity of N may be acquired and stored in the RAM 303, or the system administrator may store it in the RAM 303 in the control unit 3 of the disk array controller 10 via the CPU 1.

Next, the capacity (size) of the virtual disk device
Is determined (step S3). This is done by reading the capacity of each real disk device used for the disk array from the RAM 303 and giving it to the size calculation unit 6 from the control unit 3 through the interface 307 so that the size calculation unit 6 determines the size. In the case of the present embodiment, the size calculation unit 6 obtains the greatest common divisor of the given capacity of each real disk device, determines the value as the size of the virtual disk device, notifies the MPU 301 and stores it in the size register 5. Let it.

Next, the MPU 301 of the control unit 3 makes each of the real disk devices Disk1 to DiskN in the notified size.
Each divided area when the disk area is divided into one virtual disk device, and a disk configuration table showing the correspondence between the virtual disk device and the real disk device is created (step S4). FIG. 5 shows an example of the disk configuration table. In the disk configuration table, for each virtual disk device, the number of the real disk device indicating on which real disk device it is generated, the serial number indicating the number of the virtual disk device of the real disk device, and the like. Is recorded. The serial numbers are numbered 1, 2,... Sequentially from the head of the disk area of the real disk device. For example, as shown in FIG. 6, the serial number is N in the case of a virtual disk device DIN corresponding to a disk area from (N−1) × size to N × size from the head of a certain real disk device. The disk configuration table created as described above is stored in the RAM 303 of the control unit 3, sent to the address conversion unit 4 via the interface 306, and held as the disk configuration table 7 in the address conversion unit 4. .

Next, in order to construct one disk array using the plurality of virtual disk devices generated as described above, disk array configuration information is created, and the RAM 30
3 (step S5). This process is almost the same as the process of constructing a disk array using real disk devices, except that a virtual disk device is used instead of a real disk device. In this embodiment, the disk arrays that can be constructed are RAID0, RAID1, and R.
AID3. Which one to create is specified by the system administrator to the MPU 301 through the CPU 1, for example. Of course, if the type of RAID to be created is specified in advance by the control parameters stored in the RAM 303, the specification from the system administrator is unnecessary. Less than,
A specific configuration example of the disk array will be described for each RAID.

For convenience of explanation, there are three real disk devices D1, D2 and D3 used for the disk array, and the real disk device D3 has the smallest capacity, and the real disk device D2 has twice the capacity of the real disk device D3. It is assumed that there is a capacity, and the real disk device D1 has twice the capacity of the real disk device D2. In addition, the size calculation unit 6 determines the same value as the capacity of the real disk device D3 as the greatest common divisor. Therefore, the real disk device D1 is divided into four to generate four virtual disk devices D11, D12, D13, and D14. The real disk device D2 is divided into two to generate two virtual disk devices D21 and D22.
It is assumed that one virtual disk device D31 is generated without being divided.

(1) RAID0 In the case of RAID0, as shown in FIG. 7, four virtual disk devices D11 to D14 on the real disk device D1, and two virtual disk devices D21,
A disk array is constructed using a total of seven virtual disk devices D22 and one virtual disk device D31 on the real disk device D3. Then, logical addresses are assigned to the disk areas of each virtual disk device as indicated by 1 to n in FIG. 7, and as the disk array configuration information, for example, as shown in FIG. Information that records the number of the virtual disk device in which the area indicated by the logical address exists and the address in the disk (offset address from the head) is generated. Note that S is the size of the virtual disk device, and L is the address increment value per logical address.

(2) RAID1 In the case of RAID1, since a virtual disk device serving as a master and a virtual disk device serving as a slave are paired, an even number of virtual disk devices are used. In addition, the master virtual disk device and the slave virtual disk device do not exist on the same real disk device. A disk array corresponding to RAID 1 is configured using as many virtual disk devices as possible within a range satisfying these conditions. In the present example, as shown in FIG. 9, six virtual disk devices D1 other than the virtual disk device D14 are used.
A disk array is constructed using D1 to D13, D21, D22, and D31, and D11 and D21, D12 and D31, D
13 and D22 are each paired. Then, the logical areas shown in 1 to n in FIG. 9 are assigned to the disk areas of the respective virtual disk devices D11 to D13, D21, D22, and D31. As described above, information recording the number of the master virtual disk device, the number of the slave virtual disk device, and the in-disk address (offset address from the head) is generated for each logical address.

When an odd number of virtual disk devices are generated, the system administrator determines which one of the virtual disk devices is to be unused through the CPU 1.
The UPU 301 may designate the last virtual disk device (the one farthest from the head of the disk area) of the last real disk device in which the maximum number of virtual disk devices have been generated, for example. You may do it. Furthermore, the system administrator may specify the virtual disk devices to be paired to the MPU 301 through the CPU 1, and the MPU 301 itself sets the master virtual disk device and the slave virtual disk device on the same real disk device. The determination may be made by solving a combination problem that seeks as many pairs as possible within a range that satisfies a condition that does not exist.

(3) RAID3 In the case of RAID3, the MPU 301 uses a virtual disk device in a real disk device with the smallest number of virtual disk devices generated as a parity disk and a virtual disk device generated on another real disk device. Are used as data disks to construct a disk array equivalent to RAID3. Therefore, in the present example, as shown in FIG.
A virtual disk device D31 on the real disk device D3 is a parity disk, and virtual disk devices D11 to D14 on real disk devices D1 and D2 other than the real disk device D3.
A disk array used by D21 and D22 as data disks is constructed. Of course, the system administrator may specify the virtual disk device used as the parity disk and the virtual disk device used as the data disk to the MPU 301 through the CPU 1. Then, each of the virtual disk devices D11 to D14, D21, D
Logical addresses are assigned to the disk areas 22 and D31 as shown in A-1 to n-6 in FIG. 11, and as the disk array configuration information, for example, as shown in FIG. In addition, information is recorded which records the number of the data virtual disk device and its disk address (offset address from the head), and the parity virtual disk device number and its disk address (offset from the head).

Next, the operation at the time of reading and writing to the disk array constructed as described above will be described.

(1) When a read request or a write request specifying a logical address is given from the RAID0 CPU 1 to the control unit 3 through the interface 2, the MPU 301 of the control unit 3
The disk array configuration information as shown in FIG. 8 is searched by its logical address, and the virtual disk device number and the in-disk address are obtained. Next, the obtained virtual disk device number is converted through the interface 306 in order to check which physical address of the real disk device corresponds to the start address of the virtual disk device having the obtained virtual disk device number. Send to Part 4.

The address translator 4 searches the disk configuration table as shown in FIG. 5 by the received virtual disk device number to obtain the actual disk device number and the serial number.
From the obtained serial number and the size of the virtual disk device stored in the size register 5, (serial number-1) × size is calculated, and the calculation result and the obtained real disk device number are transferred to the MPU 301 through the interface 306.
Return to.

The MPU 301 obtains an address on the real disk device having the returned real disk device number by adding the address in the disk to the returned calculation result, and accesses the address of the real disk device to the address. Perform processing. First, it is checked whether or not a copy of the data at the address of the real disk device exists in the cache 302, and if so, the data read from the cache 302 is returned to the CPU 1 through the interface 2 if it is a read request, CP for write request
Cache data transferred from U1 at the time of write request
02 is written to the corresponding address of the real disk device via the selector 304 at the same time. Alternatively, only the cache 302 may be updated, and data on the actual disk device may be updated when the cache 302 is flushed.

On the other hand, if there is no copy of the data at the address of the real disk device in the cache 302, in the case of a read request, the data is read from the address of the real disk device via the selector 304 and the CPU 1 And cached in the cache 302. In the case of a write request, the data passed from the CPU 1 at the time of the write request is written to the address of the real disk device via the selector 304.

(2) RAID1 (A) Read Request When a read request specifying a logical address is given from the CPU 1 to the control unit 3 through the interface 2, the MPU 301 of the control unit 3 stores the read request shown in FIG.
The disk array configuration information such as 0 is searched by its logical address, and the master-side virtual disk device number and the disk address are obtained. Next, the address translation unit 4 determines the physical address of the real disk device to which the head address of the virtual disk device having the acquired master-side virtual disk device number corresponds, as in the case of RAID0. A real disk device number and a real disk device address corresponding to the side virtual disk device number and the disk address are obtained. And
The access processing for the address of the real disk device is performed in the same manner as in the case of RAID0.

(B) Write Request When a write request specifying a logical address is given from the CPU 1 to the control unit 3 through the interface 2, the MPU 301 of the control unit 3 stores the write request shown in FIG.
The disk array configuration information such as 0 is searched by its logical address, and the master-side virtual disk device number, the slave-side virtual disk device number, and the in-disk address are obtained. Next, which physical address of the real disk device corresponds to the starting address of the virtual disk device having the acquired master-side virtual disk device number, and the virtual disk device having the acquired slave-side virtual disk device number The physical address of the real disk device corresponding to the physical address of the real disk device is determined by the address conversion unit 4 as in the case of RAID 0, and the real disk device number corresponding to the master-side virtual disk device number and the disk address And a real disk device address, and a real disk device number and a real disk device address corresponding to the slave virtual disk device number and the disk address. Then, two access processes for the address of the real disk device are performed in the same manner as in the case of RAID0. Since the master virtual disk device and the slave virtual disk device are created on different real disk devices, the master,
Updates to slaves can be performed in parallel.

(3) RAID 3 (A) Read request A read request specifying, for example, A-1 as a logical address from the CPU 1 is sent to the control unit 3 through the interface 2.
, The MPU 301 of the control unit 3
The disk array configuration information as shown in FIG. 12 stored at 03 is searched by the logical address (A-x) (x is an arbitrary value), and data corresponding to each of the logical addresses A-1 to A-6 is retrieved. Virtual disk unit number and disk address,
Then, the virtual disk device number for parity and the address in the disk are obtained.

Next, the physical address of each real disk device corresponding to the obtained virtual disk device number for the data and the virtual disk device number having the virtual disk device number for the parity corresponds to RAID0.
In the same manner as in the case of (1), the real disk device number and the address in the real disk device corresponding to the data virtual disk device number and the address in the disk, the virtual disk device number for parity and the address in the disk are obtained. Of the real disk device number and the address in the real disk device corresponding to the above.

Then, the read processing for the address of the real disk device is performed in the same manner as in the case of RAID 0, and the data stored in the logical addresses A-1 to A-6 and the parity thereof are obtained. At this time, access to virtual disk devices on different real disk devices can be performed in parallel. Next, a parity check is performed. If there is no error, the data corresponding to the logical address A-1 requested to be read is returned to the CPU 1, and if there is an error, the fact is returned to the CPU 1.

(B) Write Request A write request specifying, for example, A-1 as a logical address from the CPU 1 is sent to the control unit 3 through the interface 2.
, The MPU 301 of the control unit 3
The disk array configuration information as shown in FIG. 12 stored at 03 is searched by the logical address (A-1), and the data virtual disk device number, disk address, and parity corresponding to the logical address A-1 are retrieved. Obtain the virtual disk device number for use and the address in the disk.

Next, the physical address of the real disk device corresponding to the obtained virtual disk device number for data and the virtual disk device number having the virtual disk device number for parity correspond to which physical address in RAID0.
In the same manner as in the case of (1), the real disk device number and the address in the real disk device corresponding to the data virtual disk device number and the address in the disk, the virtual disk device number for parity and the address in the disk are obtained. Of the real disk device number and the address in the real disk device corresponding to the above.

Then, the read process for the address of the real disk device is performed in the same manner as in the case of RAID 0, and the data stored at the logical address A-1 and its parity are obtained. Since the data virtual disk device and the parity virtual disk device are created on different real disk devices, they can be processed in parallel.

Next, the acquired data of the logical address A-1, the data passed from the CPU 1 at the time of the write request,
A new parity is generated from the acquired parity, and the parity and the data passed from the CPU 1 are written in RA.
As in the case of ID0, the data is written back to the cache 302 or the original location of the real disk device. At this time, the processing can be performed in parallel.

FIG. 13 is a block diagram of another embodiment of the disk array device of the present invention. This embodiment is different from the embodiment shown in FIG.
A size setting register 20 in which a system administrator can set an arbitrary value through the CPU 1, the interface 2, and the control unit 3 is provided. The size calculation unit 6 has a maximum common capacity of a plurality of real disk devices used for the disk array. If the number is smaller than the value set in the size setting register 20, the value set in the size setting register 20 is determined as the size of the virtual disk device.
The point is that the obtained greatest common divisor is determined as the size of the virtual disk device.

For example, a 2 GB real disk device,
In a case where there are two real disk devices including a GB real disk device, in the embodiment shown in FIG.
According to the MB, a total of eight virtual disk devices are generated. If, for example, 1 GB is set in the size setting register 20, the size of the virtual disk device becomes 1 GB.
Three 1 GB virtual disks are created. This allows
Although 0.2 GB is unused, it is possible to avoid a situation where the size of the virtual disk device becomes extremely small.

FIG. 14 is a block diagram of still another embodiment of the disk array device of the present invention. This embodiment differs from the embodiment shown in FIG. 2 in that the size calculation unit 6 is eliminated, and the system administrator can directly set the size of the virtual disk device in the size register 5 through the CPU 1, the interface 2, and the control unit 3. That's the point. Since the system administrator must determine the size of the virtual disk unit, the workload of the system administrator increases, but the advantage is that the system administrator can adjust the size of the virtual disk unit and the total number of virtual disk units. is there.

[0047]

As described above, according to the present invention,
To configure a disk array using multiple virtual disk units of the same capacity, including multiple virtual disk units created on the same physical disk unit, use multiple real disk units of different capacities to configure all disk units. It is possible to construct a large-capacity disk array equal to or nearly equal to the total capacity.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of an embodiment of the present invention.

FIG. 2 is a block diagram of an embodiment of a disk array device according to the present invention.

FIG. 3 is a block diagram of an embodiment of a control unit.

FIG. 4 is a flowchart illustrating an example of a procedure for constructing a disk array using a plurality of real disk devices.

FIG. 5 is a diagram showing an example of a disk configuration table.

FIG. 6 is a diagram showing the correspondence between virtual disks and real disks.

FIG. 7 illustrates an R configured using a plurality of virtual disk devices.
FIG. 3 is a diagram illustrating a configuration example of a disk array of AID0.

FIG. 8 illustrates an R configured using a plurality of virtual disk devices.
FIG. 14 is a diagram illustrating an example of disk array configuration information for a disk array of AID0.

FIG. 9 illustrates an R configured using a plurality of virtual disk devices.
FIG. 3 is a diagram illustrating a configuration example of a disk array of AID1.

FIG. 10 is a diagram illustrating an example of disk array configuration information for a RAID 1 disk array configured using a plurality of virtual disk devices.

FIG. 11 is a diagram illustrating a configuration example of a RAID3 disk array configured using a plurality of virtual disk devices.

FIG. 12 is a diagram illustrating an example of disk array configuration information for a RAID3 disk array configured using a plurality of virtual disk devices.

FIG. 13 is a block diagram of another embodiment of the disk array device of the present invention.

FIG. 14 is a block diagram of still another embodiment of the disk array device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... CPU 2 ... Interface 3 ... Control part 4 ... Address conversion part 5 ... Size register 6 ... Size calculation part 7 ... Disk configuration table 10 ... Disk array controller (DAC) 11 ... Virtual disk configuration part 20 ... Size setting register

Claims (7)

[Claims] 1. A virtual disk device when each of a plurality of real disk devices having different capacities of at least two real disk devices having different capacities is divided into disk regions of the same capacity is used as a virtual disk device. A disk array device comprising a plurality of virtual disk devices of the same capacity, including a plurality of virtual disk devices generated in the above. 2. A disk array device comprising: a plurality of real disk devices having at least any two real disk devices having different capacities; and a control device connected to the plurality of real disk devices. The apparatus includes: a size register that holds a size for dividing a disk area of the plurality of real disk devices; and an individual disk area obtained by dividing the plurality of real disk devices by the size as a virtual disk device. Means for generating a disk configuration table indicating the correspondence relationship with the real disk devices, and means for configuring a disk array using a plurality of virtual disk devices, including a plurality of virtual disk devices generated on the same real disk device And when a read / write request to the disk array is made from a higher-level device, the disk configuration The disk array apparatus comprising: a means for converting said in address to the real disk device from the corresponding address for the virtual disk device with reference to the table. 3. The disk array device according to claim 2, wherein a disk array corresponding to RAID0 is configured using all the generated virtual disk devices. 4. A disk corresponding to RAID 1 using as many virtual disk devices as possible within a range satisfying a condition that a master virtual disk device and a slave virtual disk device do not exist on the same real disk device. 3. The disk array device according to claim 2, wherein said disk array device comprises an array. 5. The RAI using a virtual disk device in a real disk device with the smallest number of virtual disk devices generated as a parity disk and a virtual disk device generated on another real disk device as a data disk, respectively.
3. The disk array device according to claim 2, wherein a disk array corresponding to D3 is configured. 6. The apparatus according to claim 2, further comprising means for obtaining a greatest common divisor of the capacities of said plurality of real disk devices, wherein the value obtained by said means is set in said size register.
The disk array device according to the above. 7. A size setting register for holding a minimum size, and means for obtaining a greatest common divisor of the capacities of the plurality of real disk devices, wherein a value obtained by the means is smaller than the minimum size. 6. The disk array device according to claim 2, wherein the minimum size is set in the size register, and the other values are set in the size register otherwise.