JP2006252165A - Disk array device and computer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To flexibly construct the configuration of a logical drive in extending the capacity of an RAID. <P>SOLUTION: A capacity extension confirming part 12 detects whether or not a first logical drive constructed of a physical drive (HDD4-1) having a plurality of block units has been added with another physical drive (HDD4-2), and when the other physical drive is detected, a write-in position determining part 13 determines which physical drive of the HDD4-1 and HDD4-2 should be stored with the respective data stored in the plurality of blocks of the physical drive (HDD4-1), and the data are successively stored by every block unit so that a new first logical drive(new first logical drive) can be constructed of the HDD4-1 and the HDD4-2. Then, as for an area where any data are not stored, another logical drive(second logical drive) is constructed by an RAID control part 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a disk array device, and more particularly to a disk array device having a function of expanding the capacity of a disk.

RAID (Redundant Arrays) is a technology that improves the reliability and speed of recording and playback devices using physical drives such as HDDs (Hard Disk Drives).
of Independent (Inexpensive) Disks).

This RAID includes striping, mirroring, parity check, ECC (Erro
r Check and Correct), data and parity, ECC distributed writing, etc., and various levels such as RAID0 to RAID6, RAID0 + 1, RAID10 / 30/50, etc. There is.

For example, RAID0 is also called striping, and stores data by dividing one piece of data. In particular, the processing speed can be increased by simultaneously reading and writing on multiple HDDs. In addition, RAID5 saves “parity”, which is information for restoration, while saving the data divided by striping to multiple HDDs, so even if one HDD breaks, it is saved on the remaining HDD. Since data can be restored by the parity being used, both speed and security can be achieved.

By the way, in the state where a RAID is conventionally constructed with a predetermined number of HDDs, another H
When capacity expansion is performed by adding a DD, the capacity of the added HDD is simply an increase in the capacity of the logical drive.

For example, in a state where RAID 0 is constructed with one HDD of 80 GB capacity,
Further, when trying to construct RAID 0 by adding an HDD with the same 80 GB capacity, the additional capacity is also used as an existing logical drive, and the capacity of one logical drive is simply 80
It only increased from GBytes to 160 GBytes.

Accordingly, since the increased capacity is always incorporated into the existing logical drive, it is not possible to perform a flexible configuration of the logical drive such that a new logical drive is newly configured when the capacity is expanded.

In Patent Document 1, as an example of steps for flexibly configuring a logical drive, a disk array is configured using a plurality of virtual disk devices having the same capacity, including a plurality of possible disk devices generated on the same real disk device. As a result, a technique is disclosed in which a plurality of real disk devices having different capacities can be used to configure a large capacity disk array that is the same as or close to the total capacity of all the disk devices.
JP 2000-298556 A (page 8, FIG. 1)

However, the technique disclosed in Patent Document 1 merely constructs a disk array using a plurality of virtual disks in order to efficiently use a plurality of real disks having different capacities. Therefore, even if the technique of the above-mentioned document 1 is used, when a disk array is already constructed in one logical drive, the configuration of the logical drive when capacity expansion is performed is flexibly constructed. I couldn't.

Therefore, the present invention has been made to solve the above-described problem. When a disk array is already constructed in one logical drive, the capacity is expanded by maintaining the capacity of the disk array. It is an object of the present invention to provide a disk array device and a computer system that can use the increased amount as another logical drive and can flexibly construct the configuration of the logical drive.

In order to solve this problem, the disk array device according to the present invention is different from the first logical drive in which a RAID is constructed at a predetermined RAID level by at least one physical drive having a plurality of block units. Detecting means for detecting whether or not another physical drive has been added, and data stored in the plurality of blocks of the at least one physical drive when the other physical drive is detected by the detecting means A storage position determining means for determining in which physical drive the data is stored in the plurality of blocks of the at least one physical drive in the physical drive determined by the storage position determining means Storage means for sequentially storing each time, and at least one of the data not stored by the storage means It has features that it has a construction means for constructing a second logical drive in physical drive and regions of said other physical drives.

In addition, the other disk array device according to the present invention can change the RAID level with respect to the first logical drive in which a RAID is constructed at a predetermined RAID level by a plurality of physical drives having a plurality of block units. Detecting means for detecting whether another physical drive is added when requested, and when the other physical drive is detected by the detecting means, the plurality of blocks of the plurality of physical drives; The data stored in the RAI
Storage position determination means for determining which physical drive to store in consideration of the change in the D level, and stored in the plurality of blocks of the plurality of physical drives in the physical drive determined by the storage position determination means Storage means for sequentially storing the existing data along the requested RAID level, and a second logical drive in the areas of the plurality of physical drives and the other physical drives for which data is not stored by the storage means And having a construction means for construction.

In the computer system according to the present invention, is another physical drive added to the first logical drive in which a RAID is constructed at a predetermined RAID level by at least one physical drive having a plurality of block units? Detecting means for detecting whether or not, and when the other physical drive is detected by the detecting means, in which physical drive the data stored in the plurality of blocks of the at least one physical drive is stored And a storage unit for sequentially storing data stored in the plurality of blocks of the at least one physical drive for each block unit in the physical drive determined by the storage position determination unit. The at least one physical drive in which data is not stored by the storage means, and the Is a feature that in the region of the physical drive having the construction means for constructing a second logical drive.

Furthermore, the computer system according to the present invention, when a change in the RAID level is requested to the first logical drive in which a RAID is constructed at a predetermined RAID level by a plurality of physical drives having a plurality of block units. Detecting means for detecting whether another physical drive has been added, and when the other physical drive is detected by the detecting means,
A storage position determining means for determining which physical drive stores the data stored in the plurality of blocks of the plurality of physical drives in consideration of the change of the RAID level; and the storage position determining means Storage means for sequentially storing the data stored in the plurality of blocks of the plurality of physical drives in the physical drive so as to follow the requested RAID level, and the plurality of data for which no data has been stored by the storage means And a construction means for constructing a second logical drive in the physical drive area and the other physical drive area.

  It is possible to flexibly construct the logical drive configuration when expanding the RAID capacity.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a disk array controller 100 according to an embodiment of the present invention. As shown in the figure, the disk array controller 100 includes a CPU (Cen
ROM (Read Processing Unit), ROM that stores firmware and various parameters for disk array control executed by the CPU (Read)
A control processor 1 configured with only memory (RAM) and a RAM (Random Access Mem) used as a work area for disk array control
ory) 2 and HDDs 4-1, 4 which are a plurality of physical drives constituting the disk array 3.
. -2,... To which the respective ports 5-1, 5-2,... Are connected, and the HDDs 4-1, 4-2 connected to these ports 5-1, 5-2,. ,...,... Are configured by a disk controller 6 that controls reading and writing, a host interface 7 that controls communication with the host CPU of the computer system, and a bus 8 that serves as a transmission path connecting them. Note that the HDDs 4-1 and 4-2 are connected to the respective ports 5-1, 5-2,.
, ... are detachable.

The control processor 1 uses a RAID controller 1 by firmware stored in the ROM.
1 functions as a capacity expansion confirmation unit 12 and a writing position determination unit 13.

The RAID control unit 11 divides and stores data into striping units as in RAID control, for example, RAID 0, and writes the same data in a plurality of HDDs using mirroring as in RAID 1, in addition to RAID 4, As in RAID 5, data parity is generated at the time of writing, and these data and parity are converted into a plurality of HDDs 4-1, 4-.
Control to record and read in the same block of 2, ....

The capacity expansion confirmation unit 12 is a part that performs confirmation of the total capacity of the physical disks of the HDDs 4-1, 4-2,... And recognizes when a physical disk is further added by the user. .

The writing position determination unit 13 determines the position of data to be written by the RIAD control unit 11 while taking into account the configured RAID level. That is, it is determined at which position of which physical disk to write. The RAID control unit 11 controls the disk controller 6 so as to write data at the position determined by the writing position determination unit 13.

The disk array controller 100 is connected to a bus in a computer system such as a personal computer, and can communicate with the host CPU of the computer system through the bus.

  Next, the operation of the disk array controller 100 of this embodiment will be described.

FIG. 2 shows the disk array controller 1 during capacity expansion according to the first embodiment of the present invention.
10 is a flowchart showing the operation of 00. FIG. 3 is a diagram showing an example of a RAID 0 disk array before capacity expansion in the first embodiment of this invention. FIG. 4 is a diagram showing an example of a RAID 0 disk array after capacity expansion after the first embodiment of the present invention is implemented.

The RAID 0 disk array shown in FIG. 3 has one logical drive (first
It is assumed that the HDD 4-1 is allocated to six blocks and RAID 0 is constructed. Here, it is assumed that data of D0 to D5 is stored in each block as shown in FIG.

Assuming FIG. 3 as an initial state, first, the disk controller of the present invention starts the subsequent processing by adding another physical drive in addition to the existing physical drive (step S10 in FIG. 2).

In other words, when the capacity expansion confirmation unit 12 determines that there is no other physical drive added (No in step S10), the processing from step S20 onward is not performed until it is determined that there is this addition. Even if another physical drive is added, the processing after step S20 may not be performed until the user inputs capacity expansion (hereinafter, a modification of the first embodiment, and The same applies to the second embodiment).

On the other hand, if the capacity expansion confirmation unit 12 determines that another physical drive has been added (Yes in step S10), then the write position determination unit 13 determines the data write position (
Step S20). The writing position is determined in consideration of the RAID level that is constructed. In the case of FIG. 3, HD, which is one more physical drive, than the HDD 4-1.
If D4-2 is added (see FIG. 4), the order of data writing is HDD4-1.
HDD4-1, HDD4-2, HDD in order, taking into account that is constructed with RAID0
4-1, HDD 4-2, HDD 4-1.

Next, the RAID controller 11 writes (rebuilds) data based on the write position determined in step S20, and a new logical drive 1 (new first) is written in both the HDD 4-1 and the HDD 4-2. (Logical drive) is constructed (step S30).

That is, as shown in FIG. 4, the HDD 4-1 is written with data of D 0, D 2, D 4 in the order of logical addresses, and the HDD 4-2 is written with data of D 1, D 3, D 5, One logical drive is constructed.

Next, the RAID control unit 11 constructs a disk area in which no data has been written as a new logical drive (second logical drive) (step S40), and the processing of this flowchart ends. That is, the areas in which the data D0 to D5 are not written in the HDD 4-1 and the HDD 4-2 (a to f in FIG. 4) are constructed as logical drives different from the new first logical drive described above. The process ends.

By performing the above processing, a new logical drive (new first logical drive) that maintains the capacity of the conventional RAID 0 logical drive (first logical drive) using the newly added HDD. As a result, RAID 0 is constructed, and for the remaining capacity, another logical drive (second logical drive) can be constructed.

That is, in FIG. 3, for example, in the case of RAID 0 configured by constructing one logical drive (first logical drive) with HDD 4-1 having a capacity of 240 GB, 240 GB
When the HDD 4-2 having the capacity of te is added, as shown in FIG.
A new logical drive (new first new logical drive) having a capacity of 240 GB is allocated to the two physical drives 1 and HDD 4-2, and the remaining 240 GB
Thus, another logical drive (second logical drive) is constructed.

Therefore, according to the request of the user, it is possible to construct RAID 0 in the second logical drive as in the case of the new first logical drive, or it is possible to construct a RAID such as RAID 1, which is a different RAID level.

Therefore, since the HDD capacity expansion can be used as another logical drive without increasing the capacity of the first logical drive before capacity expansion, it is possible to flexibly construct the structure of the logical drive during RAID capacity expansion. It becomes.

Note that FIG. 3 shows RAID 0 as an example only, but the present invention is not limited to RAID 0. As will be described later, other RAID levels such as RAID 5 or even RAID are used.
It can also be applied to level changes.

(Modification of the first embodiment)
A modification of the first embodiment of the present invention will be described below. In the first embodiment described above, the case of RAID 0 has been described. However, the present invention is not limited to RAID 0 as in the present modification, and can be implemented at other RAID levels. 5 and 6 show RAID 5 as one of modifications.

FIG. 5 is a diagram showing an example of a RAID 5 disk array before capacity expansion in a modification of the first embodiment of the present invention. The RAID 5 disk array of FIG.
It is assumed that one logical drive (first logical drive) is configured with a capacity of 720 Gbytes with three physical disks, HDD4-2 and HDD4-3, and each HDD is allocated to six blocks. Here, each block includes HDD 4-1 and HDD 4-in order.
2, HDD4-3, HDD4-3, HDD4-2, HDD4-1, HDD4-1 ... H
In the order of DD4-1, D0, D1, P0-1, D2, P2-3, D3, P4-5, respectively.
... D11 data is stored.

Here, P indicates a parity which is data restoration information. For example, P0-1 is D
Parity of 0 and D1 is shown. Parity is based on the data to be restored.
The ID control unit 11 is derived by calculating an exclusive OR.

In the state of FIG. 5, in addition to the existing physical drive, other physical drive units (HDD4-
4) is added (Yes in step S10 in FIG. 2), the writing position determination unit 13
The write position is determined in consideration of the RAID level (step S20).

In the case of FIG. 5, since it is constructed with RAID 5, the order of writing is HD in order.
D4-1, HDD4-2, HDD4-3, HDD4-4, HDD4-4, HDD4-3,
Drives to be written are determined in the order of HDD4-2, HDD4-1, HDD4-1,.

Next, based on the write position determined in step S20, the RAID controller 11 writes data, and a new logical drive (new first logical drive) having a capacity of 640 GB is constructed with RAID5 (step S30). ).

Accordingly, D0, D5, D6, and P9-11 are stored in the HDD 4-1 in the order of logical addresses, and D1, D4, P6-8, D11 are stored in the HDD 4-2, and D2, P3-5 are stored in the HDD 4-3.
, D7, D10, HDD4-3 D2, P3-5, D7, D10, HDD4-4 P
0-2, D3, D8, D9 are stored. In the above storage, since the number of physical drives is increased from three to four, the RAID control unit 11 recalculates the parity (P).

For example, P0-1 is calculated using D0, D1, and D2.

Next, the RAID control unit 11 constructs a 320 Gbyte disk area (indicated as a to h in FIG. 6) in which data has not been written as another logical drive (second logical drive) (step S40).

Therefore, according to the request of the user, it is possible to construct RAID 0 in the second logical drive as in the case of the new first logical drive, or it is possible to construct a RAID such as RAID 1, which is a different RAID level.

Accordingly, since the capacity expansion of the HDD can be used as another logical drive without increasing the capacity of the first logical drive before capacity expansion, the configuration of the logical drive can be flexibly constructed when expanding the capacity of the RAID. It becomes possible.

(Second Embodiment)
Next, the operation of the disk array controller 100 according to the second embodiment of this invention will be described.

FIG. 7 shows the disk array controller 1 at the time of capacity expansion according to the second embodiment of the present invention.
10 is a flowchart showing the operation of 00. In FIG. 7, the same parts as those in the flowchart of the first embodiment in FIG. 2 are denoted by the same symbols, and the description thereof is omitted.

The flowchart in FIG. 7 differs from the flowchart in FIG. 2 in that step S10 in FIG.
Step S50, which is a step for determining whether or not there has been a RAID level change request between Step S20 and Step S20, and if it is determined in Step S50 that there has been a RAID level change (Yes in Step S50) ) Is that step S55, which is a step of determining the writing position in consideration of this level change, is added.

FIG. 8 is a diagram showing an example of a RAID 1 disk array before capacity expansion according to the second embodiment of this invention. FIG. 9 shows R after capacity expansion after implementing the second embodiment of the present invention.
It is the figure which showed the example of the disk array of AID5.

In the disk array of FIG. 8, it is assumed that RAID 1 composed of two HDDs is constructed. That is, it is assumed that the HDD 4-1 and the HDD 4-2 are each composed of six blocks and store data of D0, D1, D2, D3, D4, and D5, respectively. Although FIG. 8 shows RAID 1 as an example only, the present invention is not limited to RAID 1, and other RAID levels may be used as much as possible.

In this embodiment, a case where a RAID level change from RAID 1 to RAID 5 is requested at the time of capacity expansion is taken as an example. In other words, in the state of FIG. 8, in addition to the existing physical drive, another physical drive unit (HDD 4-3) is added (Yes in step S10), and the user changes the level to RAID 5 via the host interface 7. It is assumed that it has been requested (Yes in step S50). It should be noted that a predetermined level change may be automatically requested by adding a physical drive.

Next, the writing position determination unit 13 determines the writing position in consideration of the change in the RAID level (step S55).

That is, in FIG. 8, since HDD 4-3 as one physical drive is added to HDD 4-1 and HDD 4-2 and the RAID level is further changed from 1 to 5, HDD 4-1 and HDD 4 in order. -2, HDD 4-3, HDD 4-3, HDD 4-2, HDD 4-
1 and the drive to be written in the order of HDD 4-1... (See FIG. 9).

Next, based on the write position determined in step S55, the RAID control unit 11 writes data (rebuild) to construct a new logical drive (new first logical drive) (step S30). Specifically, D0, D3, and P4-5 are stored in HDD4-1, D1, P2-3, and D4 are stored in HDD4-2, and P1- is stored in HDD4-3.
2, D2, D5 are stored. In the case of this example, since the RAID 1 is changed to RAID 5, the RAID control unit also calculates the parity. For example, P0-1 is D0 and D1
It will be calculated from. Since the process in step S40 is the same thereafter, the description thereof is omitted.

By performing the above processing, a new logical drive (new first logical drive) is used without increasing the capacity of the conventional RAID1 logical drive (first logical drive) using the newly added HDD. As a result, the RAID level is changed to RAID5, and another logical drive (second logical drive) can be constructed for the remaining capacity.

That is, in FIG. 8, for example, the HDD 4-1 and the HDD 4-2 having a capacity of 480 GB are 1
In the case of RAID 1 configured by constructing two logical drives (first logical drives), when HDD 4-3 having a capacity of 240 GB is further added, as shown in FIG. A new logical drive (new first logical drive) having a capacity of 360 GBytes is allocated to the three physical drives of the HDD 4-3, and the remaining 360
Another logical drive (second logical drive) is constructed for the capacity (ai) of GByte.

Therefore, according to the user's request, it is possible to construct RAID 5 in the second logical drive in the same manner as the new first logical drive, or it is possible to construct a RAID such as RAID 1, which is a different RAID level.

Accordingly, since the capacity expansion of the HDD can be used as another logical drive without increasing the capacity of the first logical drive before capacity expansion, the configuration of the logical drive can be flexibly constructed when expanding the capacity of the RAID. It becomes possible.

1 is a diagram showing a configuration of a disk array controller 100 according to an embodiment of the present invention. 3 is a flowchart showing the operation of the disk array controller 100 during capacity expansion according to the first embodiment of the present invention. FIG. 3 is a diagram showing an example of a RAID 0 disk array before capacity expansion in the first embodiment of the present invention. The figure which showed the example of the disk array of RAID0 after capacity expansion after implementing the 1st Embodiment of this invention. The figure which shows the example of the disk array of RAID5 before the capacity expansion in the modification of the 1st this Embodiment of this invention. The figure which showed the example of the disk array of RAID0 after capacity expansion after implementing the modification of the 1st Embodiment of this invention. 10 is a flowchart showing the operation of the disk array controller 100 during capacity expansion according to the second embodiment of the present invention. The figure which shows the example of the disk array of RAID1 before the capacity expansion in the 2nd Embodiment of this invention. The figure which showed the example of the disk array of RAID5 after capacity expansion after implementing the 2nd Embodiment of this invention.

Explanation of symbols

1 Control processor 2 RAM
3 Disk array 4-1, 4-2, 4-3, 4-4 HDD
5-1, 5-2, 5-3 Port 6 Disk controller 7 Host interface 8 Bus 11 RAID control unit 12 Capacity expansion confirmation unit 13 Write position determination unit 100 Disk array controller

Claims (10)

Detecting means for detecting whether or not another physical drive is added to the first logical drive in which a RAID is constructed at a predetermined RAID level by at least one physical drive having a plurality of block units;
Storage position determining means for determining which physical drive stores data stored in the plurality of blocks of the at least one physical drive when the other physical drive is detected by the detecting means; ,
Storage means for sequentially storing data stored in the plurality of blocks of the at least one physical drive for each block unit in the physical drive determined by the storage position determination means;
A disk array device comprising: a construction means for constructing a second logical drive in an area of the at least one physical drive and the other physical drive for which data has not been stored by the storage means. The disk array device according to claim 1, wherein the detection unit is implemented when a RAID capacity expansion request is made. 2. The disk array device according to claim 1, wherein the first logical drive constitutes a RAID 0 or RAID 5 disk array. RAI at a predetermined RAID level by a plurality of physical drives having a plurality of block units
Detecting means for detecting whether or not another physical drive has been added to the first logical drive in which D is constructed, when a change in the RAID level is requested;
Which physical drive stores the data stored in the plurality of blocks of the plurality of physical drives in consideration of the change of the RAID level when the other physical drive is detected by the detection unit Storage position determining means for determining
Storage means for sequentially storing the data stored in the plurality of blocks of the plurality of physical drives in the physical drive determined by the storage position determination means so as to follow the requested RAID level;
A disk array device comprising: a construction means for constructing a second logical drive in the areas of the plurality of physical drives and the other physical drives for which data has not been stored by the storage means. The first logical drive is RAID 1 and the requested RAID level is RAID
2. The disk array device according to claim 1, wherein the disk array device is ID5. Detecting means for detecting whether or not another physical drive is added to the first logical drive in which a RAID is constructed at a predetermined RAID level by at least one physical drive having a plurality of block units;
Storage position determining means for determining which physical drive stores data stored in the plurality of blocks of the at least one physical drive when the other physical drive is detected by the detecting means; ,
Storage means for sequentially storing data stored in the plurality of blocks of the at least one physical drive for each block unit in the physical drive determined by the storage position determination means;
A computer system comprising construction means for constructing a second logical drive in an area of the at least one physical drive and the other physical drive for which data has not been stored by the storage means. The computer system according to claim 1, wherein the detection unit is implemented when a RAID capacity expansion request is made. The computer system according to claim 1, wherein the first logical drive forms a RAID 0 or RAID 5 disk array. RAI at a predetermined RAID level by a plurality of physical drives having a plurality of block units
Detecting means for detecting whether or not another physical drive has been added to the first logical drive in which D is constructed, when a change in the RAID level is requested;
Which physical drive stores the data stored in the plurality of blocks of the plurality of physical drives in consideration of the change of the RAID level when the other physical drive is detected by the detection unit Storage position determining means for determining
Storage means for sequentially storing the data stored in the plurality of blocks of the plurality of physical drives in the physical drive determined by the storage position determination means so as to follow the requested RAID level;
A computer system comprising: construction means for constructing a second logical drive in the areas of the plurality of physical drives and the other physical drives for which data has not been stored by the storage means. The first logical drive is RAID 1 and the requested RAID level is RAID
The computer system according to claim 9, wherein the computer system is ID5.

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