JP2003337722A - Computer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that under a virtual reality condition, even if a data prefetch method is simply used in a storage device, it is still difficult to heighten a data reading speed. <P>SOLUTION: A control server which controls a physical data area as a virtual data area comprises an instruction sending means which sends an instruction to a corresponding storage device to retrieve data from a disc onto a cache according to an access request from servers. The storage device which receives the instruction comprises a data retrieving means which retrieves the data onto the cache according to the instruction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system in which a management server manages a data area of a storage device as a virtual data area.

[0002]

2. Description of the Related Art In recent years, the amount of data stored in a storage device has significantly increased, and the storage capacity of the storage device itself and the number of storage devices, file servers, etc. connected to a SAN (Storage Area Network) have increased. There is.
As a result, management of the large-capacity storage area becomes complicated,
Various problems such as complicated management of storage devices installed in dispersed locations and load concentration on the storage devices have appeared. Currently, a technique called virtualization is being researched for the purpose of solving these problems.
Being developed.

The virtualization technology is Evaluator.
White paper "Virt" published by Group in September 2000
As described in "Ualization of Disk Storage" (WP-0007-1), it is roughly classified into three types.

First, each server connected to the SAN shares information for managing the storage area of the storage device connected to the SAN, and each server uses the volume manager of each server. The storage device is accessed.

The second is a system configuration called in-band virtualization. In this configuration, the management server collectively stores the storage areas of the storage devices connected to the SAN in the virtual data area (hereinafter, “virtual volume”).
The management server receives requests from each server to the storage device, accesses the storage area of the subordinate storage device, and returns the result to the server.

[0006] The third is a system configuration called out-band virtualization. In this configuration as well, the management server collectively manages the storage areas of the storage devices connected to the SAN. However, when the management server receives a request for access to the storage device from the server, the management server returns the position information of the storage area that actually stores the data to the server. The server accesses the storage area of the storage device based on the returned information.

The mainstream of storage devices is to use a magnetic disk as a recording medium. When a magnetic disk is used as a recording medium, the time required for data seek on the magnetic disk and data transfer from the magnetic disk becomes a problem.

Therefore, a cache memory is provided in the storage device to predict the data requested by the host, in particular, the data to be continuously read (sequential data),
A data pre-reading method has been realized in which the data is pre-read on the cache memory. This technology is based on ACM SIGMETRICS '98
The paper `` An analytic behavi published in P182-P191
or model for disk drives with readahead caches and
Request reordering ”. By the pre-reading of the data, the time required for the data seek on the magnetic disk and the data read from the magnetic disk is hidden, and the data read performance is improved. This technology
This is referred to as data prefetch processing.

[0009]

The above-mentioned data prefetching technique is effective in the storage device alone. However, under the virtualization environment, the data areas on one or a plurality of storage devices are collectively managed as a virtual volume. Therefore, the data to be read out is not always stored in one storage device. In such a case, it is difficult to prefetch data by the same method as the data prefetch method in the storage device alone.

It is an object of the present invention to provide a data prefetching method, an apparatus and a system for implementing the data prefetching under a virtualization environment.

[0011]

In order to achieve the above object, according to the present invention, a management server that manages a physical storage area of a storage device as a virtual volume stores data based on an access request received from each server. It has means for issuing a command to the corresponding storage device to read the data from the disk onto the cache. The storage device has means for reading data on the cache in accordance with the instruction.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The present invention is not limited to this.

A first embodiment will be described with reference to FIGS. 1 to 6. It should be noted that this embodiment is targeted for an out-band type virtualization environment.

FIG. 1 shows a first system to which the present invention is applied.
It is a figure showing an embodiment of. This system includes a management server 100, a storage device 110, a server 120, a network 130 to which these are connected, and a management server 100.
Dedicated network 13 that connects the server to each server 120
2, and a dedicated network 134 that connects the management server 100 and each storage device 110.
The storage device 1 connected to the network 130
The numbers of 10 and servers 120 may be single or plural.

Communication between the management server 100 and each server 120, and communication between the management server 100 and each storage device 110,
Each dedicated network 132 and network 13
It is done via 4. Data transfer between the server 120 and each storage device 110 is performed via the network 130. With this configuration, the virtual address translation instruction 400, the physical address information 420, and the on-cache instruction 450, which will be described later, are transmitted / received using the dedicated network without using the network 130, and therefore, on the network 130. Traffic is reduced.

The management server 100 is a dedicated network 1
I / F (A) 101 connected to 32, I / F (C) 103 connected to network 130, control device 105, memory 10
8 and the I / F (B) that connects to the dedicated network 134
Has 107. The management program 1 is stored in the memory 108.
02, mapping information 104 and access history information 10
6 is stored. Control device 10 of management server 100
5 manages the physical storage area of the storage device 110 connected to the network 130 as a virtual volume which is a virtual storage area.
To execute.

The storage device 110 is the network 1
It has an I / F (A) 113 connected to 30, a control device 112, a cache 114, a disk device 116, an I / F (B) 115 connected to a dedicated network 134, and a memory 117. The control device 112 controls the cache 114 and the disk device 116, and controls data writing and data reading with respect to the designated physical storage area in response to a request from the server 120.

In this figure, the disk device 116
Although it is shown as a single unit, a plurality of disk devices 116 may be used, such as RAID. In the latter case, the control device 112 manages the correspondence between the plurality of disk devices 116 in the storage device 110 and the physical storage area. Further, even if the physical storage area provided by the storage device 110 corresponds to the disk device 116 one-to-one,
A plurality of disk devices 116 may correspond to one physical storage area. Arrows 150, 152, 15 in FIG.
Reference numerals 4, 156, and 158 are visual representations of processing when the server 120 accesses data on the storage device 110. Hereinafter, a virtual data area that can be specified by a virtual volume ID and a virtual block address is a virtual block, that address is a virtual address, and a physical data area that can be specified by an address of a storage device, a logical unit number, and a logical block address. Physical block,
The address will be called a physical address.

When accessing the data on the storage device 110, the server 120 first sends a virtual address conversion instruction 400 to the management server 100 in order to obtain the physical address of the data to be accessed (arrow 15).
0).

The I / F (A) 101 of the management server 100 receives the virtual address conversion command 400 from the server 120. Then, the control device 105 executes the management program 102, refers to the mapping information 104, and acquires the physical address corresponding to the virtual address designated by the instruction. Then, the management server 100 outputs the physical address information 420, which is information about the acquired physical address, to the I / F.
(A) Reply to the requesting server 120 via 101 (arrow 154). The server 120 having received the physical address information 420 from the management server 100 uses the physical address included in the information to access the data on the storage device 110 (arrow 158).

The control unit 105 of the management server 100 further executes a management program to determine whether the current data access is a data read based on the information contained in the received virtual address conversion instruction 400. In the case of data read, the management server 100 executes I / O to the storage device 110 storing the read data.
The F (B) 107 issues an on-cache instruction 450 (arrow 152). Further, the control device 10 of the management server 100
Reference numeral 5 refers to the access history information 106 to determine whether or not the current data access is a part of continuous data reading. When it is determined that the data is continuously read, the control device 105 of the management server 100 acquires the physical address corresponding to the virtual block in which a certain amount of data following the data currently read exists, and all the corresponding storages are acquired. The on-cache instruction 450 is issued from the I / F (B) 107 to the device 110 (arrow 152).

I / F (B) 115 of storage device 110
Receives the on-cache instruction 450 from the management server 100, the control device 112 controls the disk 116 and the cache 114, and reads the data 210 designated by the on-cache instruction 450 from the disk device 116 to the cache 114 (arrow). 156).

FIG. 2 is a diagram showing a configuration example of the mapping information 104 stored in the memory 108 of the management device 100. The mapping information 104 is the management server 100.
Has storage device information 200 that is information on the storage device 110 managed by the virtual machine, and virtual volume information 210 that associates a virtual block with a physical block. In this embodiment, both the virtual area and the physical area are managed in units of blocks, but other units, for example, some blocks are collectively managed as one management unit. Is also good.

The storage device information 200 has a storage device ID 202 that identifies the storage device 110 managed by the management server 100, a storage device address 204 that indicates the device address of this storage device 110 on the network 130, and this storage device 110. The cache size 206 indicates the capacity of the cache 114.

The virtual volume information 210 is a storage that indicates a virtual volume ID 212 that identifies a virtual volume, a virtual block address 214 that indicates the position of a virtual block within this virtual volume, and a storage device 110 that has a physical block that corresponds to this virtual block. Device ID 2
16, a logical unit number 218 indicating the physical block,
It is composed of a logical block address 220. Note that FIG. 2 shows an example in which the storage device S01 has a physical block corresponding to a virtual block in the virtual volume VVOL1, and the storage device S02 has a physical block corresponding to a virtual block in the virtual volume VVOL2. . However, one storage device may have physical blocks corresponding to a plurality of virtual volumes.

FIG. 3 shows the memory 108 of the management server 100.
3 is a diagram showing a configuration example of access history information 106 stored in FIG.

The access history information 106 is the virtual address translation instruction 40 issued for the purpose of reading data.
Read history information 300, which is history information of 0, and read ahead history information 3 that is history information of the read ahead instruction when predicting a storage area to be read in the near future and instructing read ahead
Have twenty.

The read history information 300 includes a server ID 302 for identifying the server 120 that issued the virtual address conversion command 400, a process ID 304 indicating a process in the server 120 that issued this command, and a virtual volume to which the data to be read belongs. Volume I indicating
D306, a start virtual block address 308 indicating the start virtual block of the data to be read, a end virtual block address 310 indicating the end virtual block of the data to be read, and time information 312 that is information of the time when the instruction is received. It

The prefetch history information 320 is a virtual volume ID 3 indicating the virtual volume to which the prefetched data belongs.
22, a virtual block address 324 indicating the first virtual block of this data, a virtual block address 326 indicating the last virtual block of this data, and time information 328 indicating the issuance time of the on-cache instruction 450 issued for prefetching To be done.

In FIG. 4, the server 120 is the management server 100.
Virtual address translation instruction 400 issued to the management server 1
00 sent to the server 120 by the physical address information 42
0 is a diagram showing a configuration example of an on-cache instruction 450 issued to the storage device 110 by the management server 100.

The virtual address conversion instruction 400 includes a control code 402 for identifying this instruction, an access flag 404 indicating whether the data access request by this instruction is a data read request or a data write request, and the server 120 that issued this instruction. A server ID 406 for identifying, a process ID indicating a process in the server 120 that issued this instruction
408, virtual address information 410 indicating a virtual address of data to be accessed.

The virtual address information 410 includes a virtual volume ID 412 indicating the virtual volume to which the access target data belongs, a start virtual block address 414 indicating the start virtual block of the access target data, and an end indicating the end virtual block of the access target data. It is composed of a virtual block address 416.

The physical address information 420 has a control code 422 for identifying this information and a physical address list 430 which is a list of physical addresses corresponding to the virtual addresses designated by the virtual address conversion instruction 400.

The physical address list 430 is a virtual volume ID designated by the virtual address conversion instruction 400.
432 and a virtual block address 434, and a storage device address 436 which is a physical address corresponding to the virtual address, a logical unit number 438, and a logical unit address 440.

The on-cache instruction 450 has a control code 452 for identifying this instruction and a data address list 460 for specifying data to be read into the cache 114.

The data address list 460 includes a logical unit number 462 which stores data to be read,
First logical block address 464 indicating the first physical block of the data to be read, last logical block address 466 indicating the last physical block of the data to be read
Composed of.

FIG. 5 and FIG. 6 are diagrams showing the flow of data access processing in the first embodiment. The operation when the server 120 reads data from or writes data to the storage device 110 will be described below. Here, the process executed by the management server 100 is a process executed by the control device 105 executing the management program 102 stored in the memory 108.
5 and 6, when the access flag 404 in the virtual address translation instruction 400 indicates the reading of data,
That is, an example is shown in which the pre-reading process is performed both when the request from the server 120 is a data read request and when it is predicted that the data read request from the server 120 is a part of continuous data read requests. ing. However, the prefetching process may be performed only in either case.

The server 120 uses the virtual address translation instruction 4
The necessary information is set in 00 and transmitted to the management server 100 (step 500). Here, the information to be set is a control code 402 indicating that the instruction is a virtual address translation instruction, an access flag 404 indicating whether the data access is read or write, a server ID 406 indicating the server issuing this instruction, the corresponding information. A process ID 408 indicating a process that issues an instruction, a virtual volume ID 412 to which the access target data belongs, a start virtual block address 414 of this data, and an end virtual block address 4
Sixteen.

Upon receipt of the virtual address conversion command 400, the management server 100 searches the virtual volume information 210, and the storage device ID2 corresponding to the virtual block address specified by the virtual address information 410 in the command.
16, the logical unit number 218, and the logical block address 220 are calculated. Further, the management server 100 searches the storage device information 200 by using the storage device ID 216 determined in the above search as a key, and the network 13
The device address 204 of the storage device on 0 is acquired (step 502).

The management server 100 refers to the access flag 404 in the virtual address translation instruction 400 to determine whether the request is a data read or a data write. The management apparatus 100 continues the process from step 506 in the case of data read and from step 518 in the case of data write (step 504).

The management server 100 uses the read history information 3
00, a new entry is added, and the server ID 406 and the process ID 408 in the virtual address translation instruction 400 are added.
The server ID 302 and the process I of the new entry in which the virtual volume ID 412, the start virtual block address 414, and the end virtual block address 416 are added, respectively.
D304, the virtual volume ID 306, the start virtual block address 308, and the end virtual address 310 are copied, and the time when the above command is accepted is set in the time information 312 (step 506).

The management server 100 searches the prefetch history information 320 from the present time to a predetermined period before, and checks whether the data to be read this time has already been read in the cache 114 of the storage device 110 by the previous processing. (Step 508).

If the data to be read this time has already been read into the cache 114, step 5
18, the management server 100 continues the process from step 512 if not read (step 51).
0).

The management server 100 sets the necessary information in the on-cache instruction 450 for each storage device 110 determined in step 502, and issues the on-cache instruction 450 for each relevant storage device 110 (step 512). Here, the information to be set is the control code 452 indicating that the instruction is an on-cache instruction, and the information in the data address list 460 for specifying the physical position where the data to be read is actually stored. is there. The logical unit number 462 in the data address list 460, the start block address 464 and the end block address 466 in this logical unit are set to the logical unit number and the logical block address determined in step 502. If the data to be read is divided and stored in a plurality of logical units, information of all the relevant logical units and physical blocks is set in the data address list 460. Further, the management server 100 uses the dedicated network 134 to issue an on-cache instruction 45 to all the storage devices 110 connected to the dedicated network 134.
0 may be broadcast, or the address of the storage device 110 on the dedicated network 134 may be designated and the on-cache command 450 may be transmitted for each storage device 110.

Upon receipt of the on-cache command 450, the storage system 110 caches the data of all physical blocks designated by the data address list 460.
14 (step 514).

The management server 100 determines whether or not the on-cache instruction 450 has been issued to all the relevant storage devices 110, and if so, from step 518,
If not issued, the process continues from step 512 (step 516).

The management server 100 sets the physical address determined in step 502 in the physical address information 420, and the server 120 that issued the address translation command 400.
And the process is continued from step 600 (step 518).

The server 120 that has received the physical address information 420, from the physical address list 430, stores all the storage devices 110 that store the data to be accessed.
And the physical block address are acquired (step 520).

The server 120 accesses the storage device 110 storing the data to be accessed based on the information acquired in step 520 (step 522).

The management server 100 refers to the access flag 404 in the received virtual address translation instruction 400,
Determine whether the purpose of the request is to read or write data. When reading data, the management server 100 continues the process from step 602, and when writing data, the management server 100 ends the process (step 60).
0).

The management server 100 uses the read history information 3
00 is checked to see if this read request is part of a continuous data read request (step 602). Here, the determination as to whether or not it is a continuous data read request is performed as follows, for example. Read history information 300
The history information regarding the data read from the storage device 110 by the server 120 in the past is stored in the. The management server 100 stores the server ID 302, the process ID 304, and the process ID 304 stored in the read history information 300.
By referring to the time information 312, the same server as the data read request received this time and the same process read the data of the virtual block in the same virtual volume within a predetermined period (for example, several seconds before or several minutes before). If the virtual block following the virtual block is continuously read, it is determined that the current data read request is also a part of a series of continuous data read requests.

When it is determined that the current read request is a part of continuous data read requests, the management server 1
00 continues the process from step 606, and when it is determined that it is not, the process ends (step 604).

The management server 100 stores a fixed amount (for example, the number of blocks read in one read operation when reading continuous data) from the virtual block next to the last virtual block of the data that is the current read target. The virtual block is identified as the prefetch target data (step 606).

The management server 100 searches the virtual volume information 210, determines all the physical blocks corresponding to each of the above-mentioned pre-read target virtual blocks, and determines the ID 216 of the storage device having the physical block and the logical unit number 218. And the logical block address 220 of the physical block. Further, the management server 100 searches the storage device information 200 by using the acquired storage device ID 216 as a key, and acquires the device address of the storage device having the corresponding physical block (step 608).

The management server 100 sets the required information in the on-cache instruction 450 for each storage device 110 having the physical block determined in step 608, and issues the on-cache instruction 450 for each storage device 110 (step). 610). here,
The information set is similar to the information set in step 512.

The storage device 110 that has received the on-cache instruction 450 reads the data of all the physical blocks specified by the data address list 460 onto the cache 114 (step 612).

The management server 100 determines whether or not the on-cache command 450 has been issued to all the corresponding storage devices 110, and if it has issued, the process continues from step 616, and if it has not issued, the process continues from step 610 ( Step 614).

The management server 100 uses the prefetch history information 32.
A new entry is added to 0, the virtual volume ID of the data read ahead this time, the top virtual block address,
End virtual block address, on-cache instruction 450
Is set, and the process ends (step 616).

In this embodiment, the management server 10
0 transmits the on-cache instruction 450 to the storage device 1 before transmitting the physical address information 420 to the server 120.
Issued on 10. However, the order of transmitting the physical address information 420 to the server 120 and issuing the on-cache instruction 450 to the storage device 110 may be reversed or simultaneous.

According to the first embodiment, the management server 10 is operated under the out-band type virtualization environment.
0 can instruct the storage device 110 to read the corresponding data from the disk 116 onto the cache 114 based on the inquiry regarding the data access received from each server 120. Therefore, each storage device 110 can efficiently perform a data read process.

Further, according to the first embodiment, when the management server 100 receives the inquiry, it predicts the storage area in which the data will be read in the future based on the history information regarding the past data read, and the corresponding storage is performed. Prefetching can be instructed to the storage device 110 having an area. That is, it is possible to instruct prefetching of data even for a storage area that has not yet received the virtual address conversion instruction 400 from each server 120. Therefore, even under the out-band type virtualization environment, each storage device 110 can efficiently perform the data pre-reading process, and the time required for reading a continuous series of data can be shortened.

As a result, in the virtualization environment, the time required for the data seek in the disk device and the data transfer from the disk device can be hidden, and the data reading process can be speeded up.

FIG. 7 shows a second system according to the present invention.
It is a figure showing an embodiment of. The difference from the first embodiment is that the dedicated line 132 connecting the management server 100 and each server 120, and the management server 100 and each storage device 1 are connected.
The point is that the dedicated line 134 for connecting with 10 does not exist in the second embodiment. Therefore, between the management server 100 and each storage device 110, between the management server 100 and each server 12
During the time 0, all communication between each server 120 and each storage device 110 is performed via the network 130. Therefore, the traffic on the network 130 is increased as compared with the first embodiment, but it is not necessary to prepare the dedicated networks 132 and 134 in the first embodiment. The process when the server 120 reads data from the storage device 110 or when the server 120 writes data to the storage device 110 is executed according to the process flow shown in FIGS. 5 and 6 as in the first embodiment. It However, in the second embodiment, the management server 1
00 uses the network 130 for the storage device 1
The on-cache instruction 450 is issued to 10. Therefore, the management server 100 is the network 1
An on-cache instruction 4 is specified for each storage device 110 by specifying the address of the storage device 110 on
The difference from the first embodiment is that 50 is transmitted.

According to the second embodiment, when the server 120 reads data from the storage device 110, the management server 100 instructs the storage device 110 via the network 130 to read the data into the cache 114. be able to. Therefore, it is possible to perform efficient prefetch processing at low cost.

FIG. 8 shows a third system of the present invention.
It is a figure showing an embodiment of. The present embodiment targets an in-band virtualization environment. This embodiment is different from the first embodiment in the data access method. In the third embodiment, the server 120 requests the management server 100 for data access, and the management server 1
00 accesses the data on the storage device 110 according to the request. Incidentally, in the present embodiment, the management server 100 uses the cache 80 for transmitting and receiving data to and from the storage device 110 and the server 120.
Has 0.

Arrows 810, 812, 81 in FIG.
Reference numerals 4 and 816 are visual representations of the data access method according to the third embodiment.

The server 120 transmits a data access command 900 to the management server 100 when accessing the data on the storage device 110 (arrow 810). Upon receiving the data access command 900 from the server 120, the management server 100 refers to the mapping information 104 and acquires the physical address corresponding to the virtual address specified by this command. Further, the management server 100 determines from the information associated with this command whether the current access request is data write or data read, and in the former case, transfers the write target data from the server 120 to the cache 800 (arrow 8).
16), write in the physical block pointed to by the acquired physical address (arrow 814). In the latter case, the management server 10
0 issues an on-cache instruction 450 to all the storage devices 110 that store the data to be read (arrow 812). Then, the management server 100 reads the data to be read from the corresponding storage device 110 onto the cache 800 (arrow 814), and transmits it to the requesting server 120 (arrow 816).

In FIG. 9, the server 120 is the management server 100.
3 is a diagram showing the configuration of a data access instruction 900 issued to the. The data access instruction 900 is a control code 902 that identifies this instruction, an access flag 904 that indicates whether data access by this instruction is data read or data write, a server ID 906 that identifies the server 120 that issued this instruction, Server 12 that issued this instruction
A process ID 908 indicating a process in 0, virtual address information 910 indicating a virtual address of data to be accessed, a transfer destination of data to be accessed, or a buffer address 920 indicating an address of a buffer on the server 120 which is a transfer source. Have.

The virtual address information 910 includes a virtual volume ID 912 indicating the virtual volume to which the access target data belongs, a start virtual block address 914 indicating the start virtual block of the access target data, and an end indicating the end virtual block of the access target data. It is composed of a virtual block address 916.

10 and 11 are diagrams showing the flow of data access processing in the third embodiment. Less than,
The operation when the server 120 reads out the data stored in the storage device 110 through the management server 100 or writes the data in the storage area on the storage device 110 will be described. Note that the processing performed by the management server 100 is performed by the control device 105 of the management server 100 in the memory 10
8 is executed by executing the management program 102 stored in FIG.

The server 120 receives the data access instruction 90.
The necessary information is set to 0 and transmitted to the management server 100 (step 1000). Here, the information to be set includes a control code 902 indicating that the instruction is a data access instruction, an access flag 904 indicating whether the data access is read or write, a server ID 906 indicating the server that issues this instruction, and the corresponding information. Process ID 908 indicating the process that issues the instruction, virtual volume ID 912 to which the data to be accessed belongs, start virtual block address 914 of this data, end virtual block address 9 of this
16, a buffer address 920 indicating the address of the buffer on the server 120 that is the transfer destination or the transfer source of the data to be accessed.

The management server 100, which has received the data access command 900, searches the virtual volume information 210 and finds all physical blocks corresponding to each virtual block specified by the virtual address information 910 in the command, I of the storage device having the physical block
The D216, the logical unit number 218, and the logical block address 220 are acquired. Further, the management server 100 searches the storage device information 200 by using the acquired storage device ID 216 as a key, and acquires the device address of the storage device having the physical block (step 10).
02).

The management server 100 refers to the access flag 904 in the data access instruction 900 to determine whether the request is a data read or a data write. The management server 100 starts from step 1100 when reading data, and starts from step 1006 when writing data.
Continues processing (step 1004).

The management server 100 is the server 1 indicated by the buffer address 920 in the data access instruction 900.
Data is transferred from the buffer on 20 to the cache 800 (step 1006).

The management server 100 writes the data transferred in step 1006 in the physical block determined in step 1002 (step 1008).

The management server 100 judges whether or not all the data to be written has been written in the storage device 110, and if it has been written, the processing is terminated, and if it has not been written, the processing is continued from step 1008 (step 1010). ).

The management server 100 uses the read history information 3
00, a new entry is added to the data access command 900, and the server ID 406, process ID 408, virtual volume ID 412, and start virtual block address 4 in the data access command 900 are added.
14, the end virtual block address 416, the server ID 302, the process ID 304, and the virtual volume I, respectively.
D306, the start virtual block address 308, and the end virtual address 310 are copied, and the time when the above instruction is accepted is set in the time information 312 (step 1100).

The management server 100 searches the prefetch history information 320 within an arbitrary period from the present time, and investigates whether the data to be read this time has already been read in the cache 114 of the storage device 110 by the prefetch process. (Step 1102).

If the data to be read this time has already been read into the cache 114, step 1
112, Step 110 if not read
From 6, the management server 100 continues the process (step 1104).

The management server 100 has the storage device 110 having the physical block determined in step 1002.
The necessary information is set in the on-cache instruction 450 for each, and the on-cache instruction is issued for each corresponding storage device 110 (step 1106). here,
The information set is the same as the information set in step 512 shown in FIG. The storage device 110 that has received the on-cache command 450 reads the data of the physical block specified by the data address list 460 onto the cache 114 (step 110).
8).

The management server 100 judges whether or not the on-cache instruction 450 has been issued to all the corresponding storage devices 110, and if so, continues the processing from step 1112, and if not, continues the processing from step 1106 ( Step 1110).

The management server 100 reads the data to be read this time from the corresponding storage device 110 into the cache 800 on the management server (step 1112).

The management server 100 determines whether or not all the data to be read this time have been read into the cache 800, and if read, continues from step 1116, and if not read, continues processing from step 1112 (step 1114).

The management server 100 transfers the data read from the storage device 110 to the cache 800 to the data area on the server 120 indicated by the buffer address in the data access instruction 900 received this time (step 1116), and the processing shown in FIG. The processing shown in FIG. 6 is executed from step 602.

According to the third embodiment, the management server 100 under the in-band virtualization environment.
However, based on the data access command received from each server 120, the storage device 11 reads the data to be accessed from the disk 116 onto the cache 114.
You can specify 0. Therefore, the data reading process can be efficiently performed.

Further, when the data access command is accepted, the management server 100 predicts the storage area in which the data to be read in the future is stored, based on the history information related to the past data read, and the corresponding storage area. The storage device 110 having the above is instructed to prefetch data. That is, the management server 100 can instruct the prefetching of data even for a storage area that has not yet received a data access command from each server 120. Therefore, even in the in-band virtualization environment, the storage device 110 can efficiently perform the data pre-reading process, and the time required for reading a continuous series of data can be shortened.

[0087]

According to the present invention, prefetching of data can be executed even in a virtualization environment.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a system to which the present invention has been applied.

FIG. 2 is a diagram showing a configuration example of mapping information included in a management server.

FIG. 3 is a diagram showing a configuration example of access history information included in a management server.

FIG. 4 is a diagram showing a configuration example of a virtual address conversion instruction issued by the server to the management server, physical address information transmitted by the management server to the server, and an on-cache instruction issued by the management server to the storage device.

FIG. 5 is a diagram showing an example of a data access process.

FIG. 6 is a diagram showing an example of a data access process.

FIG. 7 is a diagram showing a second embodiment of a system to which the present invention has been applied.

FIG. 8 is a diagram showing a third embodiment of a system to which the present invention has been applied.

FIG. 9 is a diagram showing a configuration example of a data access command issued by a server to a management server.

FIG. 10 is a diagram showing an example of a data access process according to the third embodiment.

FIG. 11 is a diagram showing an example of a data access process according to the third embodiment.

[Explanation of symbols]

100 ... Management server 102 ... Management program 104 ... Mapping information 106 ... Access history information 110 ... Storage device 114 ... cache 116 ... Disk device 120 ... server

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Taka Oeda             1099 Ozenji, Aso-ku, Kawasaki City, Kanagawa Prefecture             Ceremony company Hitachi Systems Development Laboratory (72) Inventor Yasuto Yamamoto             1099 Ozenji, Aso-ku, Kawasaki City, Kanagawa Prefecture             Ceremony company Hitachi Systems Development Laboratory (72) Inventor Kensuke Eguchi             1099 Ozenji, Aso-ku, Kawasaki City, Kanagawa Prefecture             Ceremony company Hitachi Systems Development Laboratory F term (reference) 5B065 BA01 CC02 CH01 CH05                 5B082 FA03 FA05 FA07

Claims (17)

[Claims] 1. A management server connected to a server and one or more storage devices, comprising: a physical storage area of each of the one or more storage devices; and a virtual volume that is a virtual storage area. Means for storing the correspondence relationship of the virtual volume, means for receiving the address of the virtual volume from the server, and means for converting the address of the virtual volume to the address of the physical storage area based on the correspondence relationship, Means for transmitting the address of the physical storage area to the server, and an instruction for reading data stored in the storage area to a storage device having the storage area indicated by the address of the physical storage area A management server having means for transmitting. 2. The management server according to claim 1, further comprising a prediction unit that predicts a storage area in which data to be read is stored, based on an address of the virtual volume received from the server, The management server, wherein the means for transmitting a command for reading data transmits a command for reading the data stored in the storage area to the storage device having the storage area predicted by the prediction means. 3. A management server connected to a server device and one or more storage devices, comprising: an interface unit connected to the server device and the one or more storage devices; and the one or more storage devices. A physical storage area of the storage device, a storage device that stores a correspondence relationship between a virtual volume that is a virtual storage area, and a control device that controls the interface unit and the storage device. The address of the virtual volume is received from the server device, the control device converts the address of the virtual volume into the address of the physical storage area based on the correspondence relationship stored in the storage device, and the interface The section writes to the storage device having the storage area indicated by the address of the physical storage area. Management server and transmits the address of the physical storage area to read the data stored in the area. 4. The management server according to claim 3, wherein the interface unit includes a first interface unit connected to the one or more storage devices and a second interface unit connected to the server device. A management server, wherein the second interface unit receives the address of the virtual volume, and the first interface unit transmits the address of the physical storage area. 5. The management server according to claim 4, wherein the second interface unit further transmits the address of the physical storage area to the server device. 6. The management server according to claim 4, wherein the first interface unit further stores data stored in a storage area indicated by an address of the physical storage area,
A management server, which receives from a storage device having the storage area, and the second interface unit transmits the data received by the first interface unit to the server device. 7. The management server according to claim 3, wherein the interface unit further transmits the address of the physical storage area to the server device. 8. The management server according to claim 3, wherein the storage device further stores information regarding an access history to a storage area of the one or more storage devices, and the control device includes the access history. Predicts a storage area to be accessed based on information about the storage area, and the interface unit reads out the data stored in the storage area from the storage device having the predicted storage area. A management server characterized by transmitting the. 9. A computer system comprising a server device, one or more storage devices, and a management server connected to the server device and the one or more storage devices, wherein the management server is the server. A device and a first interface unit for connecting to the one or more storage devices, a physical storage area of the one or more storage devices, and a virtual volume that is a virtual storage area. A storage device that stores the storage device, and a first control device that controls the first interface unit and the storage device, wherein each of the one or more storage devices is a second device for connecting to the management server. An interface section, a disk device that constitutes the physical storage area, a cache memory, the second interface section, A second control device for controlling the cache memory, the first interface unit receives an address of a virtual volume from the server device, and the first control device receives the virtual The address of the volume is converted into a logical address that is an address of a physical storage area based on the correspondence stored in the storage device, and the first interface unit converts the logical address.
The second interface unit receives the logical address, and the second control unit transmits to the storage device having the physical storage area indicated by the logical address, and the second control unit indicates the disk device indicated by the logical address. A computer system which controls to read data stored in the upper storage area to the cache memory. 10. The computer system according to claim 9, wherein the first interface unit connects with a third interface unit for connecting with the server device and the one or more storage devices. A fourth interface unit, the third interface unit receives an address of the virtual volume from the server device, and the fourth interface unit sends the logical address to the storage device. A computer system characterized by. 11. The computer system according to claim 10, wherein the third interface unit further transmits the logical address to the server device, and the server device stores a storage area indicated by the logical address. A computer system which reads data stored in a cache memory of a storage device of the computer. 12. The computer system according to claim 10, wherein the fourth interface unit is further stored in a cache memory of a storage device having a storage area indicated by the logical address. A computer system, which receives data, and wherein the third interface unit further transmits the data received by the fourth interface unit to the server device. 13. The computer system according to claim 9, wherein the first interface unit transmits the logical address to the server device, and the server device has a storage having a storage area indicated by the logical address. A computer system for reading data stored in a cache memory of a device. 14. The computer system according to claim 9, wherein the storage device of the management server further stores information regarding access history to a disk device included in each of the one or more storage devices, The first control device predicts a physical storage area to be accessed based on the information regarding the access history, and the first interface unit stores the physical storage area in the storage device having the predicted physical storage area. Transmitting a logical address indicating a storage area, the second interface unit receives the logical address, the second control device from the physical storage area indicated by the logical address to the physical storage area A computer system characterized by controlling the stored data to be read into the cache memory. 15. A method in which a management server that manages a physical storage area of one or a plurality of storage devices as a virtual storage area instructs the one or a plurality of storage devices to read data. A step of receiving a virtual address which is an address of the virtual storage area from a server device, and the virtual address being a logical address indicating a physical storage area corresponding to the virtual storage area indicated by the virtual address. A step of converting, and for the storage device having the physical storage area,
A step of transmitting the logical address so as to read the data stored in the physical storage area. 16. The data read instruction method according to claim 15, further comprising the step of transmitting the logical address to the server device. 17. The data read instruction method according to claim 15, further comprising the step of predicting a physical storage area on the one or more storage devices accessed by the server device based on the virtual address. A logical address indicating the predicted physical storage area,
A method of instructing reading of data, comprising the step of transmitting to a storage device having the physical storage area.