JP2012252638A - Disk array device and method of controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk array device capable of improving write performance.SOLUTION: The disk array device includes one control part without redundant configuration for controlling writing of data received from a host device to a memory device, a first memory control part for storing the data received from the control part in a first memory, and a second memory control part for storing the data received from the first memory control part in a second memory. When the data is stored in the second memory, the control part transmits a notification indicating the completion of writing of the data into the memory device to the host device.

Description

  The present invention relates to a disk array device and a control method thereof.

  Conventionally, as an entry model for a disk array device, it is expensive but has a redundant configuration (operation can be continued in the event of a failure), a dual model with high data transfer performance, and an inexpensive but no redundant configuration (at the time of failure) A single model with low transfer performance is widely known.

  As a single model disk array device, for example, a disk array device disclosed in Patent Document 1 is disclosed. The disk array device of Patent Document 1 includes a single controller that controls a plurality of disks that store information, a cache memory provided in the single controller that temporarily stores information, and cache data storage that stores data in the cache memory. And a cache data protection controller for protecting data in the cache memory. In the disk array device of Patent Document 1, at least one of a cache data storage memory and a cache data protection controller is mounted independently of a single controller.

  As a single model disk array device, for example, a storage device disclosed in Patent Document 2 is disclosed. In the storage device of Patent Document 2, when the controller 3 receives a write command from the host, the write data received from the host is written in each cache area, the write data is stored redundantly, and the write data is stored in each cache area. Immediately after each writing, the host is notified of the completion of processing of the write command.

JP 2008-269221 A JP 2006-092120 A

  Compared with the dual model, the cost of the single model disk array apparatus can be reduced because only one controller is required. However, since a single model disk array apparatus has to send a completion notification after writing received data to the disk drive, performance degradation (write performance degradation) occurs and there is only one controller. Loss of redundancy (operation stop at the time of failure) occurs.

  The loss of redundancy is an effect only when a failure occurs, whereas the performance degradation is constantly affected during daily operations. That is, the single model disk array device has a problem that the write performance is constantly reduced as compared with the dual model.

  The present invention has been made in consideration of the above points, and proposes a disk array device and a control method thereof that can improve the write performance.

  In order to solve such a problem, one aspect of the disk array device of the present invention is configured to control writing of data received from a host device to a storage device, one control unit not configured redundantly, and receiving from the control unit A first memory control unit for storing the data in a first memory; and a second memory control unit for storing the data received from the first memory control unit in a second memory; When the data is stored in the second memory, the control unit transmits a notification that the writing of the data to the storage device is completed to the host device.

  Further, according to one aspect of the disk array device control method of the present invention, the first memory control unit controls writing of data received from the host device to the storage device, from one control unit that is not redundantly configured. A first step of storing the received data in a first memory; and a second step of a second memory control unit storing the data received from the first memory control unit in a second memory. And, when the data is stored in the second memory, the control unit transmits a notification to the host device that the writing of the data to the storage device is completed. It is characterized by providing.

  Therefore, although it is an inexpensive single model disk array device, it is possible to suppress a decrease in write performance that occurs in principle because it is a single model in the prior art, and to ensure performance equivalent to the dual model.

  According to the present invention, it is possible to realize a disk array device capable of improving write performance and a control method thereof.

It is a figure which shows an example of a structure of a storage system. It is a flowchart which shows an example of a data write processing procedure. It is a figure which shows an example of a structure of the storage system of another Example.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited thereby.

(Constitution)
FIG. 1 is a diagram showing an example of the configuration of the storage system 1 of the present embodiment. The storage system 1 includes, for example, a host device 2 and a disk array device 3. The host device 2 and the disk array device 3 are connected via, for example, a predetermined neckwork.

  The host device 2 is a computer device including, for example, information processing resources such as a CPU (Central Processing Unit) and a memory, an information input device, and an information output device. For example, the host device 2 transmits a write request to the disk array device 3 and writes corresponding data to the disk array device 3. For example, the host device 2 transmits a read request to the disk array device 3 and reads the corresponding data from the disk array device 3.

  As the predetermined network, for example, a local area network (LAN), a storage area network (SAN), the Internet, a dedicated line, a public line, and the like can be used as appropriate.

  The disk array device 3 includes, for example, a controller unit 4 and a plurality of hard disk devices 5. The disk array device 3 includes one controller unit 4. That is, the disk array device 3 is a single model disk array device. The controller unit 4 controls the entire disk array device 3. The plurality of hard disk devices 5 store data received from the host device 2.

  The controller unit 4 includes, for example, a host adapter unit 6 and a disk adapter unit 7. The host adapter unit 6 includes, for example, a processor 11, a first cache controller 12, and a first cache memory 13.

  The processor 11 is connected to the host apparatus 2 via a network and controls transmission / reception of various requests and data received from the host apparatus 2. The processor 11 can use various interfaces according to the type of network.

  Further, the processor 11 interprets the received various requests and transmits an instruction to each component. Further, the processor 11 performs RAID (Redundant Arrays of Inexpensive / Independent Disks) control on the hard disk device 5 to improve the reliability, availability, and performance of the disk array device 3. In this case, the processor 11 sets one or more logical volumes on a physical storage area (RAID group) provided by one or more hard disk devices 5. The data is stored in units of blocks of a predetermined size in this logical volume.

  The first cache controller 12 controls the first cache memory 13 to read / write (read / write) data received from the host device 2 and data received from the plurality of hard disk devices 5 to the first cache memory 13. To do.

  The first cache memory 13 temporarily holds data received from the host device 2 and data received from the plurality of hard disk devices 5.

  The disk adapter unit 7 includes, for example, a second cache controller 14, a second cache memory 15, and a switch 16.

  The second cache controller 14 is connected in series with the first cache controller 12, controls the second cache memory 15, receives data received from the host device 2 and the plurality of hard disks from the second cache memory 15. Read / write data received from the device 5.

  The second cache memory 15 temporarily holds data received from the host device 2 and data received from the plurality of hard disk devices 5.

  The switch 16 is connected to the plurality of hard disk devices 5 and controls transmission / reception of data received from the host device 2 and data received from the plurality of hard disk devices 5. The switch 16 can use various interfaces corresponding to types such as Fiber Channel, SAS (Serial Attached SCSI), SATA (Serial ATA), and the like.

  The plurality of hard disk devices 5 hold data received from the host device 2.

  The disk array device 3 according to the present embodiment uses the controller unit 4 including the first cache controller 12, the first cache memory 13, the second cache controller 14, and the second cache memory 15. A means for suppressing deterioration is provided.

  The host adapter unit 6 and the disk adapter unit 7 are physically independent from each other, and a cache memory backup system also exists independently. The host adapter unit 6 and the disk adapter unit 7 can be individually replaced in the event of a component failure.

(Data write processing procedure)
Next, the operation of the storage system 1 of this embodiment will be described in detail. FIG. 2 is a flowchart showing data write processing of the disk array device 3 of the present embodiment.

  When receiving data to be written from the host device 2, the processor 11 starts the data write processing procedure RT1 shown in FIG. 2, and transmits the data received from the host device 2 to the first cache controller 12 (step SP1).

  Subsequently, the first cache controller 12 stores the data received from the processor 11 in the first cache memory 13 (step SP2). Subsequently, the first cache controller 12 transmits the data received from the processor 11 to the second cache controller 14 (step SP3).

  Subsequently, the second cache controller 14 stores the data received from the first cache controller 12 in the second cache memory 15 (step SP4). Subsequently, the second cache controller 14 transmits a data write completion notification for notifying that the data has been stored in the corresponding hard disk device 5 to the processor 11 via the first cache controller 12 (step SP5).

  Subsequently, the processor 11 transmits the data write completion notification received from the second cache controller 14 via the first cache controller 12 to the host device 2 (step SP6), and then the data write processing procedure RT1 shown in FIG. Is terminated (step SP7).

(Operation and effect)
Thus, in the single model disk array device 3 of the present embodiment, the first cache controller 12 stores the data received from the processor 11 in the first cache memory 13, and the second cache controller 14 The data received from the cache controller 12 is stored in the second cache memory 15, and when the data is stored in the second cache memory 15, the processor 11 transmits a data write completion notification to the host device 2.

  Therefore, although it is an inexpensive single model disk array device, it is possible to suppress a decrease in write performance that occurs in principle because it is a single model in the prior art, and to ensure performance equivalent to the dual model.

  Specifically, when the data is stored in the second cache memory 15, the data is made redundant in the two cache memories. Therefore, the processor 11 issues a data write completion notification to the host device 2 at this time. Can do. After that, even if data failure to the hard disk device 5 is completed after this, a component failure occurs in the host adapter unit 6 and the entire host adapter unit 6 is replaced. 7 can be used to continue and complete writing to the hard disk device 5 after the host adapter unit 6 is restored. As described above, there is no problem in transmitting the data write completion notification after the data is stored in the second cache memory 15.

  Further, since the data is made redundant in the two cache memories, even if one of the cache memories itself fails, the data stored in the other cache memory is used to Writing to the device 5 can be continued and completed.

(Other examples)
In the present embodiment, the case where the host adapter unit 6 and the disk adapter unit 7 are physically independent and can be individually replaced has been described. However, when the disk array device 3 is actually designed, the host adapter unit 6 and the disk adapter unit The pulling direction when the adapter unit 7 is replaced may be on the upper side of the paper surface as indicated by the arrow in FIG.

  For example, if a failure occurs on the disk adapter unit 7A side and an attempt is made to replace it, the host adapter unit 6A must also be removed together. At this time, the data stored in the first cache memory 13A of the host adapter unit 6A must be backed up and retained for data recovery after failure repair. However, since the information stored in the first cache memory 13A is user data, the data can be easily taken away if the data is retained even after being extracted. Therefore, in order to prevent the above data from being taken away, in the embodiment as shown in FIG. 3, when the processor 11A receives the data from the host device 2, the data is encrypted.

  A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Supplementary Note 1) One control unit that is not configured redundantly, which controls writing of data received from the host device to the storage device, and a first memory that stores the data received from the control unit in a first memory A memory control unit; and a second memory control unit that stores the data received from the first memory control unit in a second memory, wherein the control unit stores the data in the second memory. When stored, the disk array device transmits a notification to the host device that the writing of the data to the storage device is completed.

(Supplementary note 2) The disk array device according to supplementary note 1, wherein when the control unit receives the data from the host device, the control unit encrypts the data.

(Supplementary Note 3) The first memory control unit controls the writing of data received from the host device to the storage device, and stores the data received from one control unit that is not redundantly configured in the first memory. A first step; a second step in which a second memory control unit stores the data received from the first memory control unit in a second memory; and And a third step of transmitting, to the host device, a notification that the writing of the data to the storage device has been completed. .

DESCRIPTION OF SYMBOLS 1 ... Storage system, 2 ... Host device, 3 ... Disk array device, 4 ... Controller unit, 5 ... Hard disk device, 6 ... Host adapter part, 7 ... Disk adapter part, 11 ... Processor 12 …… First cache controller, 13 …… First cache memory, 14 …… Second cache controller, 15 …… Second cache memory, 16 …… Switch

Claims (3)

A control unit that is not configured redundantly and that controls writing of data received from the host device to the storage device;
A first memory control unit for storing the data received from the control unit in a first memory;
A second memory control unit for storing the data received from the first memory control unit in a second memory;
With
The controller is
When the data is stored in the second memory, a notification that the writing of the data to the storage device is completed is transmitted to the host device. The controller is
The disk array device according to claim 1, wherein when the data is received from the host device, the data is encrypted. A first memory control unit controls writing of data received from a host device to a storage device, and stores the data received from one non-redundant control unit in a first memory. When,
A second step in which a second memory control unit stores the data received from the first memory control unit in a second memory;
A third step in which, when the data is stored in the second memory, the control unit transmits a notification to the host device that the writing of the data to the storage device is completed;
A method for controlling a disk array device, comprising:

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