JP2009258911A - Disk array device, method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk array device for achieving high access performance also to sequential access. <P>SOLUTION: This disk array device 10 comprises a management map updating section 33 for updating the load information to each extent whenever it receives access data I from a host computer 5, a grouping section 34 for grouping each extent whenever it receives access data I from the host computer 5, and a rearrangement processing section 35 that detects an extent of a heavy load from the managed map by execution of an optimization command, detects an extent grouped with the extent of the heavy load, and replaces the extent group with an extent in a zone region. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a disk array apparatus, method, and program for realizing high access performance even for sequential access.

  Conventionally, in a disk array apparatus, a bottleneck or a hot spot in which an access load to an area of the HDD is concentrated occurs in an array in a logical disk or a magnetic disk drive (hereinafter also referred to as HDD). is there.

  However, in the conventional disk array device, the physical arrangement of the area of the logical disk is fixed, and the block address in the logical disk and the corresponding block address of the array or HDD do not basically change. Therefore, when an unbalanced access load from the host computer occurs in the logical disk, it cannot be easily solved.

  Recently, due to an increase in the capacity of a single HDD, a plurality of logical volumes are created in the disk array device and shared by a plurality of users. Therefore, the access load changes due to an increase in the number of host computers connected to the disk array device, and bottlenecks and hot spots are likely to occur.

Therefore, in order to cope with such a change in access load, a disk array device has been proposed that virtually manages the physical arrangement of logical disk areas (see, for example, Patent Document 1). In this disk array device, the storage area of at least one disk drive is configured as a continuous storage area of one array, and the entire area of this array is in units of “extents” configured by a collection of one or more sectors. Divide and manage. Then, in this disk array device, statistical information on the access load from the host computer is collected in units of extents, and based on this statistical information, an extent with a high access load and an extent that is unused or has a low access load are replaced Thus, adjustment is made so that the access load is not concentrated on a specific array.
JP 2006-24024 A

  However, in the disk array device described above, performance degradation may occur for accesses that are continuously processed within a certain period of time (hereinafter also referred to as sequential access).

  Supplementally, streaming data such as video distribution can be cited as an example of sequential access. Such streaming data may be stored in two or more extents. In this case, since each extent has continuity, the physical arrangement is preferably close. However, in the above disk array apparatus, the physical arrangement of extents is switched according to the access load from the host computer. For this reason, the physical arrangement of extents having continuity may be dispersed, resulting in a problem that access performance deteriorates when data is read from the viewpoint of seek time and the like.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a disk array device, method, and program that realize high access performance for sequential access.

  In order to solve the above problems, the present invention is a disk array device that manages a logical disk by dividing it into a plurality of extents, and performs data read / write processing in response to access from a host computer, and constitutes a logical disk Zone area storage means for storing a zone area in which the physical arrangement of the storage medium is close, management map storage means for storing a management map for managing load information and group information for each extent ID, and access data from the host computer Management map update means that calculates load information for each extent each time it is received, updates the management map information, grouping means that groups each extent each time access data is received from the host computer, and optimization instruction If a high-load extent is detected from the management map by executing Moni, detects extents grouped against extent of the high load, to provide a disk array and means for replacing the these extents group and extent of a zone in the region.

  According to the present invention, it is possible to provide a disk array device, method, and program that realize high access performance even for sequential access.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Configuration of disk array device)
FIG. 1 is a schematic diagram showing the configuration of a disk array device 10 according to an embodiment of the present invention.

  The disk array device 10 manages the logical disk R by dividing it into a plurality of extents x, x + 1,... N, and performs read / write processing of data stored in the extents according to access data from the host computer 5 It is. The disk array device 10 includes at least one array 20 and a controller 30.

  The disk array terminal 10 can be realized by a combination of a hardware configuration and a software configuration. In the software configuration, each function as the disk array device 10 is realized by installing a program obtained from a computer-readable storage medium or a network in advance in the computer.

  As shown in FIG. 2, the array 20 is defined as one area in which storage areas of at least one disk drive 21A,..., 21N (hereinafter also referred to as HDD) are continuous. In the present embodiment, the logical disk R of the array 20 is configured by a combination of “extents” that are a collection of one or more sectors of the HDD. Each extent has a fixed capacity.

  As shown in FIG. 3, the controller 30 includes a zone area storage unit 31, a management map storage unit 32, a management map update unit 33, a grouping unit 34, and a rearrangement processing unit 35.

  The zone area storage unit 31 is a storage device that stores a “zone area” in which the physical arrangement of HDDs constituting the logical disk 22 is close. Specifically, the zone area storage unit 31 stores the zone area in association with the extent ID. By rearranging the data in the extent based on this zone area, the physical arrangement of the extent can be made closer as shown in FIG.

  As shown in FIG. 5, the management map storage unit 32 is a storage device that stores a “management map” for managing load information and group information for each extent ID.

  The management map update unit 33 calculates load information for each extent each time access data is received from the host computer 5, and updates the management map information.

  Specifically, the management map update unit 33 generates statistical information related to access from the host computer 5 in extent units. The load for each extent is periodically analyzed based on the result of the statistical information, and the load information of the management map is updated.

  Each time the access data is received from the host computer 5, the grouping unit 34 executes “sequentiality detection processing” described later to update the group information of each extent. In FIG. 5, EXT001 to EXT003 belong to the same group A.

  The rearrangement processing unit 35 rearranges data by replacing data stored in an extent with data stored in an extent in the zone area. Specifically, upon receiving an “optimization instruction” from the host computer 5 or the like, the relocation processing unit 35 detects a high-load extent (EXT002) from the management map and is identical to the high-load extent (EXT002). The extent of the group A (EXT001, EXT003) is detected. Then, these grouped extent groups are replaced with extents in the zone area. As a result, data is rearranged from the state of FIG. 6A to the state of FIG.

(Operation of the disk array device)
Next, the operation of the disk array device 10 according to the present embodiment will be described.

  Each time the disk array device 10 according to the present embodiment receives the access data I from the host computer 5, (a) it is determined whether the access data I crosses the boundary of the extent, and (b) sequentiality. Perform detection processing. A plurality of extents are grouped by the sequentiality detection process. Thereafter, (c) optimization processing is performed in accordance with an optimization command from the host computer 5 or the like. This will be specifically described below.

(A. Extent boundary determination)
When the host computer 5 reads / writes data from / to the disk array device 10, it sends out access data I. Since the size of the access data I is smaller than the extent storage capacity, it is almost always included in the extent area (FIG. 7B). However, the access data I may straddle the extent boundary area (FIG. 7A). Therefore, when an access to the extent x (x is a variable) occurs from the host computer 5, the grouping unit 34 of the controller 30 executes the processing shown in FIG. 8 before executing the sequentiality detection processing described later. 5 determines whether the access data I from 5 crosses the boundary region of the extent x (S1 to S3).

  Specifically, the controller 30 makes a determination based on a determination formula of “start address of access + access size> first address of extent x + 1”. When it is determined that the controller 30 straddles the boundary region, the controller 30 executes the sequentiality detection process for the extent x (S3-Yes, S4), and then executes the sequentiality detection process for the extent x + 1 (S5, S6). On the other hand, when it is determined that the controller 30 does not cross the boundary region, the controller 30 executes a sequentiality detection process for the extent x (S3-No, S6).

  Then, when receiving access data having continuity from the host computer 5, the controller 30 executes the processes of S2 to S6 until the reception of all the access data is completed (S7-No, S8).

  When the reception of access data is completed, if sequential access detection processing described later detects that access data having continuity has accessed multiple extents, these extents are grouped and stored in the management map. (S7-Yes).

(B. Sequentiality detection processing)
When the controller 30 receives the access data I from the host computer 5, the grouping unit 34 executes “sequentiality detection processing”. Hereinafter, a description will be given with reference to FIG. As a premise, as shown in FIG. 10, the memory of the controller 30 stores table information indicating the target extent, access time, time interval, continuous access flag, and sequential count for each extent ID.

  First, the grouping unit 34 determines whether or not the access to the next extent x + 1 is continuously performed from the access to the extent x (T1). Specifically, the grouping unit 34 writes the access time (Ta-x) in the management table every time the extent x is accessed from the host computer 5. Then, a time interval (Tgap-i) with the previous extent x is calculated (T2), and it is determined whether or not the calculated time interval is within a threshold (T3). If the time interval is within the threshold, it is determined that the access is continuous, the continuous access flag is set to “1” (T3-No, T4), and the sequential count is incremented and written to the table information (T5, T6). ). On the other hand, if the time interval is not within the threshold value, it is determined that the access is not continuous, and the continuous access flag remains “0” (T3-Yes).

  Then, the grouping unit 34 determines whether or not the sequential count exceeds a sequential determination value that is a predetermined threshold (T7). When the sequential count exceeds the sequential determination value, the grouping unit 34 determines that the access from the host computer 5 is sequential access according to the following condition (1), and the extent accessed from the host computer 5 is determined. Group the group (T7-Yes, T8). As a result, the same group information is set for each extent ID.

If (ΣSequential count (S_count)> Sequential judgment value) then "Sequential access" ... Condition (1)
When the access data I from the host computer 5 crosses the boundary area of the extent x, the controller 30 sets the access time of the extent x and the access time of the extent x + 1 to the same time value. For the extent x, the controller 30 records the time interval (Tgap-x) with the extent x-1 accessed in the previous stage, and sets a continuous access flag by threshold determination.

(C. Optimization process)
Thereafter, when the controller 30 receives an optimization command from the host computer 5 or the like, the relocation processing unit 35 executes the relocation processing of the data stored in the extent. Specifically, the relocation processing unit 35 detects a high-load extent from the management map, and also detects extents grouped with a high-load extent. Then, the grouped extent group and the zone area extent are exchanged to rearrange the data.

(Effect of disk array device)
As described above, the disk array device 10 according to this embodiment includes the management map update unit 33 that updates the load information for each extent each time the access data I is received from the host computer 5, and the access data from the host computer 5. Each time I is received, a grouping unit 34 that groups each extent and execution of an optimization instruction detects a high-load extent from the management map, and also detects the high-load extent and a grouped extent. Since the rearrangement processing unit 35 for exchanging these extent groups and extents in the zone area is provided, the disk array device 10 that realizes high access performance for sequential access can be provided.

  In short, in the disk array device 10, the extents can be rearranged while maintaining the continuity of the physical arrangement of the grouped extent groups, and the continuous physical arrangement can be prevented from being dispersed over time. Therefore, even if the host computer 5 accesses across the boundaries of a plurality of extents, it can be processed at high speed.

  Further, according to the disk device 10, the grouping unit 34 stores table information indicating access time, time interval, and sequential count for each extent ID, and a plurality of extents are accessed from the host computer 5. The time interval between the access time to the previous extent and the access time to the subsequent extent is calculated, and if the time interval is within the threshold, the sequential count corresponding to the previous extent and the subsequent extent is updated and updated. When the set sequential count exceeds the threshold value, the extent group corresponding to the sequential count is grouped. Therefore, it can be considered that sequential data is stored in the grouped extent group. Therefore, high access performance can be realized for sequential access from the host computer.

  Further, since the disk array device 10 brings the extent groups close to each other while maintaining a continuous physical arrangement for sequential access, the HDD seek time can be shortened.

  Further, the disk array device 10 stores a management map that changes with time, and can always hold optimum grouping information. For this reason, it is possible to prevent consumption of system resources due to an increase in the retention management information with time.

  According to the disk array device 10, even when there is an extent with a low access load, if it is grouped, it cannot be replaced with an extent with a high access load other than the zone area. Specifically, as shown in FIG. 11, in the grouped extent groups s1 to s4, even if the extent s4 has a lower load than the extent c1, the extent s4 is grouped. Priority is given to c1, and a high-load extent h2 other than the zone area is rearranged. In short, in the disk array device 10, it is possible to group extents and lower the priority to be rearranged with other extents, thereby avoiding a change in physical arrangement.

  Needless to say, the disk array device 10 has an initialization function for sequentiality detection processing. As shown in FIG. 12, in accordance with an instruction from the outside, the sequential count is set to zero, the continuous access flag is set to zero, and the grouping information of the extent group to be sequentially accessed is cleared (U1 to U3). As a result, the information stored in the memory of the controller is initialized to a state as shown in FIG.

  As shown in the concept of FIG. 14, when the disk array device 10 receives a data read request of the grouped extent group from the host computer 5, the data of the grouped extent group is transferred to another extent. A function of reading ahead of data may be provided. As a result, when the host computer access occurs, the extent group data is preferentially read, so that the access performance for sequential access can be improved.

  In the disk array device 10, the zone area storage unit may store a plurality of zone areas in association with the physical arrangement of the plurality of arrays. As a result, as shown in FIG. 15, the grouped extent groups A to C can be moved to another array while maintaining the continuous physical arrangement. Therefore, the load applied to a specific array can be distributed and the access performance of the disk array device 10 can be improved.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine a component suitably in different embodiment.

  Note that the method described in the above embodiment includes a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), an optical disk (CD-ROM, DVD, etc.), a magneto-optical disk (MO) as programs that can be executed by a computer. ), And can be distributed in a storage medium such as a semiconductor memory.

  In addition, as long as the storage medium can store a program and can be read by a computer, the storage format may be any form.

  In addition, an OS (operating system) running on a computer based on an instruction of a program installed in the computer from a storage medium, MW (middleware) such as database management software, network software, and the like realize the above-described embodiment. A part of each process may be executed.

  Furthermore, the storage medium in the present invention is not limited to a medium independent of a computer, but also includes a storage medium that downloads and stores or temporarily stores a program transmitted via a LAN, the Internet, or the like.

  Further, the number of storage media is not limited to one, and the case where the processing in the above embodiment is executed from a plurality of media is also included in the storage media in the present invention, and the media configuration may be any configuration.

  The computer according to the present invention executes each process in the above-described embodiment based on a program stored in a storage medium, and is a single device such as a personal computer or a system in which a plurality of devices are connected to a network. Any configuration may be used.

  In addition, the computer in the present invention is not limited to a personal computer, but includes an arithmetic processing device, a microcomputer, and the like included in an information processing device, and is a generic term for devices and devices that can realize the functions of the present invention by a program. .

1 is a schematic diagram showing a configuration of a disk array device 10 according to an embodiment of the present invention. It is a schematic diagram for demonstrating the structure of the array which concerns on the same embodiment. It is a schematic diagram which shows the structure of the controller 30 which concerns on the same embodiment. It is a schematic diagram which shows the concept of the zone area | region which concerns on the same embodiment. It is a schematic diagram which shows the structure of the management map memory | storage part 32 which concerns on the embodiment. It is a schematic diagram which shows the concept of the rearrangement process which concerns on the same embodiment. It is a schematic diagram which shows the concept of the capacity | capacitance of the access data which concerns on the embodiment, and the storage capacity of an extent. It is a flowchart for demonstrating the process of extent boundary determination which concerns on the embodiment. It is a flowchart for demonstrating the sequentiality detection process which concerns on the same embodiment. It is a schematic diagram which shows the structure of the table information which the controller 30 concerning the embodiment memorize | stores. It is a schematic diagram for demonstrating the effect of the disk array apparatus 10 concerning the embodiment. It is a schematic diagram for demonstrating the initialization function of the sequentiality detection process which concerns on the embodiment. It is a schematic diagram which shows the structure of the table information which the controller 30 concerning the embodiment memorize | stores. It is a schematic diagram for demonstrating the modification of the disk array apparatus concerning the embodiment. It is a schematic diagram for demonstrating the modification of the disk array apparatus concerning the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 5 ... Host computer, 10 ... Disk array apparatus, 20 ... Array, 21A-21N ... Magnetic disk drive, 30 ... Controller, 31 ... Zone area storage part, 32 ... Management map storage unit 33... Management map update unit 34... Grouping unit 35. Rearrangement processing unit R R logical disk I access data.

Claims (7)

A disk array device that divides and manages a logical disk into a plurality of extents and performs read / write processing of data stored in the extents according to access data from a host computer,
Zone area storage means for storing a zone area in which the physical arrangement of the storage medium constituting the logical disk is close;
Management map storage means for storing a management map for managing load information and group information for each extent ID;
Management map update means for calculating load information for each extent each time access data is received from the host computer, and updating the information of the management map;
Grouping means for grouping each extent each time access data is received from the host computer;
By executing an optimization instruction, a high-load extent is detected from the management map, and extents grouped with respect to the high-load extent are detected, and these extent groups and extents in the zone area are exchanged. Means,
A disk array device comprising: The disk array device according to claim 1,
The disk array device according to claim 1, wherein the grouping means groups the extents when a plurality of extents are accessed within a predetermined time, or when access extends over a plurality of extents. The disk array device according to claim 1,
The grouping means includes
Means for storing table information indicating an access time, a time interval, and a sequential count for each extent ID;
Means for calculating a time interval between the access time to the previous extent and the access time to the subsequent extent when a plurality of extents are accessed from the host computer;
Means for updating a sequential count corresponding to the preceding extent and the succeeding extent if the time interval is within a threshold;
A disk array device comprising: means for grouping extent groups corresponding to a sequential count when the updated sequential count exceeds a threshold value. The disk array device according to claim 1,
When the host computer receives a read request for data of extent groups grouped by the grouping means, the data storage device includes means for reading the data of the extent groups grouped ahead of the data of other extents. A disk array device. The disk array device according to claim 1,
The zone area storage means stores a plurality of zone areas in association with a physical arrangement of a plurality of arrays. A management method used in a disk array device that manages a logical disk by dividing it into a plurality of extents and performs data read / write processing in response to access from a host computer,
Writing a zone area in which the physical arrangement of the storage medium constituting the logical disk is close to the zone area storage means;
Writing a management map for managing load information and group information for each extent ID in the management map storage means;
Calculating load information for each extent each time access data is received from the host computer, and updating the management map information;
Grouping each extent each time access data is received from the host computer;
By executing an optimization instruction, a high-load extent is detected from the management map, and extents grouped with respect to the high-load extent are detected, and these extent groups and extents in the zone area are exchanged. Steps,
A management method characterized by comprising: A program used in a disk array device that manages a logical disk by dividing it into a plurality of extents and performs data read / write processing in response to access from a host computer,
A computer of the disk array device;
Zone area storage means for storing a zone area in which the physical arrangement of the storage medium constituting the logical disk is close;
Management map storage means for storing a management map for managing load information and group information for each extent ID;
A management map update means for calculating load information for each extent each time access data is received from the host computer, and updating information of the management map;
Grouping means for grouping each extent each time access data is received from the host computer;
By executing an optimization instruction, a high-load extent is detected from the management map, and extents grouped with respect to the high-load extent are detected, and these extent groups and extents in the zone area are exchanged. means,
As a program to be realized.

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