JP2015055878A - Cache control device, cache control method, disk array device and controller of the same, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cache control device capable of suppressing the performance degradation of a disk array device even when the state and information related to I/O processing vary dynamically.SOLUTION: The cache control device 1 includes: a priority value calculation unit 2 for calculating the priority value of a cache of a cache group by a predetermined calculation on the basis of configuration information, load information, and priority information of a controller; and a cache attribute control unit 3 that determines the attribute of each cache in accordance with the calculated priority value and performs change to the determined attribute.

Description

  The present invention relates to a technical field in which an optimal cache is selected from a plurality of caches and a cache group is configured based on the selected cache.

  In a generally known disk array device (hereinafter, also referred to as “storage system”), the reliability of the data is increased and the fault tolerance is improved by making the components of the device redundant and by duplicating the data to be stored. Technology is adopted.

  More specifically, as an example, the redundancy technology includes a controller including a control unit that controls the disk array device and a cache memory (hereinafter referred to as “cache”) that temporarily stores the data. There is a technology for duplication.

  Furthermore, the control method of the cache included in the two duplicated controllers is such that the cache included in one controller is a master (hereinafter referred to as “cache master”) and the cache included in the other controller is a slave (hereinafter referred to as “cache master”). A local cache system is generally known which is configured as a “cache slave”) and controls these caches.

  Here, the cache master is, for example, data write (write) or read (read) processing (hereinafter referred to as “I / O (Input / Output) processing”) between the server device and the disk array device. This is a cache mainly used when executing The cache slave is a cache used when data held in the cache master is duplicated.

  In the local cache method, for example, when a disk array device accepts a data write request (hereinafter also referred to as “I / O request”) from a server device, the data is temporarily held in a cache master and a cache slave. As a result, the time required for the I / O processing can be shortened and the data can be duplicated.

  Here, as related technologies existing prior to the application of the present application, there are, for example, Patent Documents 1 to 3.

  Patent Document 1 discloses a technique related to a disk array device, a disk array system, and a cache control method. The disk array device disclosed in Patent Document 1 includes a master controller including a cache and a slave controller including a buffer memory (hereinafter referred to as “buffer”).

  When the slave controller receives a write data write request from the server device, the slave controller holds the write data in a buffer. The slave controller adds identification information indicating that the write data is held in the buffer to the received write request. Further, the slave controller transmits a write request to which the identification information is added and the write data to the master controller.

  The master controller receives the write request and the write data, and holds the received write data in the cache. The master controller transmits a write request to which the identification information is added to the slave controller. The slave controller changes the buffer attribute from the buffer to the cache in response to receiving the write request.

  As a result, the disk array device disclosed in Patent Document 1 is configured so that even if one controller is requested to write data to a slave controller that does not have master authority to control the other controller. Write data consistency can be maintained between the caches of the controller and the slave controller.

  Patent Document 2 discloses a technique related to an array controller, a disk array control method, and a program.

  The array controller includes a write control unit that controls to write data and redundant data of the data to a plurality of disk drives in a distributed manner, and a cache of the disk drive in which the redundant data is written among the plurality of disk drives. And a write cache control unit for setting the write back mode.

  As a result, the array controller disclosed in Patent Document 2 can reduce the time required to write data in the disk array device.

  Next, Patent Document 3 discloses a technology related to a storage cluster system having a cache consistency guarantee function. The storage cluster system includes a plurality of storage device control devices and physical storage devices managed by the storage device control device.

  The plurality of storage device control apparatuses include a storage device control apparatus that functions as a slave node that receives an access request from an external apparatus, a storage device control apparatus that functions as a master node that manages a physical storage device, a slave node, and the access And a storage device control device that functions as a directory management node that manages a directory entry that associates an access target range included in the request.

  When the slave node receives an access request from an external device, the slave node transfers the access request to the master node. When the received access request indicates a read request, the slave node holds the data transferred from the master node in response to the access request in the cache.

  On the other hand, when the received access request indicates a write request, the slave node holds the data transferred from the external device in the cache. Further, any one of the plurality of storage device control apparatuses writes data related to the virtual storage device formed in the physical storage device.

  As described above, the storage cluster system disclosed in Patent Document 3 can suppress unnecessary processing associated with a cache operation and guarantee data consistency without using dedicated hardware.

JP 2011-192053 A JP 2006-277042 A JP 2008-123198 A

  By the way, in a disk array device having two controllers, a method for assigning attributes such as master, slave, and sub-slave to the cache included in the controller is that logical storage devices such as a plurality of hard disk drives are logically predetermined. There is known a method of assigning an attribute to the cache in accordance with a Rank number that can identify a storage area (hereinafter referred to as “Rank” in the present application) configured in units.

  More specifically, as an example, as a method of assigning such an attribute, when the Rank number represents an even number, the cache included in one controller (for example, controller # 0) is used as a cache master and the other controller ( For example, a cache included in the controller # 1) is a cache slave.

  In addition, when the Rank number represents an odd number, the attribute is assigned to the cache included in one controller (controller # 1) as a cache master and the cache included in the other controller (controller # 0). A cache slave.

  In the above description, the case where the local cache method is adopted in the two controllers has been described. In the following description, for example, a case where a local cache method is adopted in a disk array device including four controllers will be described.

  More specifically, as an example, such a system forms a pair for every two controllers of the four controllers. Further, in such a system, in two controllers constituting a pair, a cache included in one controller is a cache master, and a cache included in the other controller is a cache slave. Further, such a system constitutes a pair of a cache master and a cache slave (hereinafter referred to as “cache pair”). As a result, this method can form two cache pairs.

  In addition, as a method of assigning Rank to the configured cache pair, when the Rank number represents an even number, it is assumed that assignment is made to one cache pair (for example, cache pair # 0). In addition, as a method of assigning the Rank, when the Rank number represents an odd number, the other Rank is assigned to the other cache pair (for example, cache pair # 1).

  In the method of assigning such Rank, for example, when the cache attribute (master or slave) has already been determined in one cache pair (cache pair # 0), in the other cache pair (cache pair # 1), The cache cannot be used as a cache master or cache slave.

  Therefore, the method of assigning such Rank is that when the cache attribute (master or slave) has already been determined in one cache pair (cache pair # 0), the other cache pair (cache pair # 1) The cache attribute is the cache sub-slave.

  FIG. 8 is a diagram conceptually illustrating the configuration of four controllers and cache attributes included in the four controllers.

  In FIG. 8, a physical disk array controller (Disk_Array_Controller: hereinafter referred to as “DAC”) group # 0 (first physical DAC group 201) includes controller # 0 (first controller 205) and controller in the same casing. # 2 (third controller 207). The physical DAC group # 1 (second physical DAC group 202) includes a controller # 1 (second controller 206) and a controller # 3 (fourth controller 208) in the same casing.

  The logical DAC group # 0 (first logical DAC group 203) includes a first controller 205 and a second controller 206. The logical DAC group # 1 (second logical DAC group 204) includes a third controller 207 and a fourth controller 208.

  In FIG. 8, the cache pair # 0 is configured by the cache # 0 (first cache 209) of the first controller 205 as a cache master and the cache # 1 (second cache 210) of the second controller 206 as a cache slave. The cache # 2 (third cache 211) of the third controller 207 and the cache # 3 (fourth cache 212) of the fourth controller 208 are cache subslave in the cache pair # 0.

  In the cache pair # 1, the third cache 211 is constituted by a cache master and the fourth cache 212 is constituted by a cache slave. The first cache 209 and the second cache 210 are assumed to be cache subslave in the cache pair # 1.

  In the disk array device having the configuration illustrated in FIG. 8, for example, when an I / O request is received from the server device, the response time (response time) varies depending on the cache attributes (master, slave, and subslave). .

  More specifically, as an example, the operation of the disk array device that has received an I / O request from the server device will be described with reference to FIG. 9 (FIGS. 9A, 9B, 9C, and 9D).

  FIG. 9A is a sequence diagram illustrating the flow of processing in the disk array device when the first controller 205 including the cache master shown in FIG. 8 receives a write request from the server device.

  In FIG. 9A, when the first controller 205 receives a write request from the server device, the first controller 205 transmits the data to the second controller 206 after writing the data to the first cache 209. The second controller 206 receives the data from the first controller 205 and writes the data to the second cache 210. The second controller 206 notifies the first controller 205 that the writing of the data to the second cache 210 has been completed. That is, in FIG. 9A, when the first controller 205 including the cache master receives a write request from the server device, data communication between the controllers is performed once. Further, communication between controllers is performed twice.

  FIG. 9B is a sequence diagram illustrating the flow of processing in the disk array device when the third controller 207 including the cache sub-slave illustrated in FIG. 8 receives a write request from the server device.

  In FIG. 9B, when the third controller 207 receives a write request from the server device, the third controller 207 cannot mainly execute write processing, and therefore transmits data to the first controller 205. The first controller 205 receives data from the third controller 207 and writes the data to the first cache 209.

  Further, the first controller 205 transmits the data to the second controller 206. The second controller 206 receives the data from the first controller 205 and writes the data to the second cache 210. The second controller 206 notifies the first controller 205 that the writing of the data to the second cache 210 has been completed. The first controller 205 notifies the third controller 207 that the writing of the data has been completed. That is, in FIG. 9B, when the third controller 207 including the cache sub-slave receives a write request from the server device, data communication between the controllers is performed twice. Further, communication between controllers is four times.

  FIG. 9C is a sequence diagram illustrating the flow of processing in the disk array device when the second controller 206 including the cache slave shown in FIG. 8 receives a write request from the server device.

  In FIG. 9C, when the second controller 206 receives a write request from the server device, the second controller 206 cannot mainly execute write processing, and therefore transmits data to the first controller 205. The first controller 205 receives the data from the second controller 206 and writes the data to the first cache 209.

  Further, the first controller 205 transmits the data write request to the second controller 206. The second controller 206 receives the data write request from the first controller 205 and writes the data to the second cache 210. The second controller 206 notifies the first controller 205 that the writing of the data to the second cache 210 has been completed. The first controller 205 notifies the second controller 206 that the writing of the data has been completed. That is, in FIG. 9C, when the second controller 206 including the cache slave receives a write request from the server device, data communication between the controllers is performed once. Further, communication between controllers is four times.

  FIG. 9D is a sequence diagram illustrating the flow of processing in the disk array device when the fourth controller 208 including the cache sub-slave illustrated in FIG. 8 receives a write request from the server device.

  In FIG. 9D, when the fourth controller 208 receives a write request from the server device, the fourth controller 208 cannot mainly execute write processing, and therefore transmits data to the first controller 205. That is, as described with reference to FIGS. 9A to 9C, in FIG. 9D, when the fourth controller 208 including the cache sub-slave receives a write request from the server device, data communication between the controllers is performed twice. Further, communication between controllers is four times.

  As described above, the number of communication and data communication between controllers differs according to the attribute of the cache included in the controller that has accepted the write request. That is, when the controller including the cache sub-slave receives a write request from the server device, the performance of the disk array device deteriorates.

  For this reason, for example, the user needs to connect the server device and the controller of the disk array device in consideration of the attribute of the cache included in the controller. That is, the connection work for the user may be complicated.

  Further, for example, in a disk array device, when an I / O request from a specific server device is preferentially executed according to the priority (priority order), the user can execute a cache with the specific server device. It is necessary to connect to the controller including the master or cache slave. However, when a controller including a cache master or a cache slave is already connected to another server device, the user needs to reconnect the already connected server device, the controller, and the specific server device. .

  Patent Document 1 to Patent Document 3 described above only describe a method of controlling caches in two redundant controllers. For example, it relates to I / O processing between a server device and a disk array device. There is no consideration and no mention of controlling the cache when the state or information changes dynamically. Further, Patent Documents 1 to 3 do not describe anything about the case of controlling a cache in a disk array device including four or more controllers.

  In other words, in Patent Documents 1 to 3, when the I / O load or priority between the server apparatus and the disk array apparatus is dynamically changed, the cache attribute cannot be changed appropriately. For this reason, the disk array device may not be able to stably perform I / O processing with the server device, but may cause a reduction in processing speed.

  A main object of the present invention is to provide a cache control device and the like that can prevent the performance of a disk array device from deteriorating even when a state or information related to I / O processing changes dynamically. The main purpose.

  In order to achieve the above object, a cache control device according to the present invention has the following configuration.

That is, the cache control device according to the present invention is
Configuration information of a plurality of controllers that control the disk array device, load information that indicates an I / O load in an information processing device that issues an I / O request to the disk array device, and priority information that indicates a priority in the information processing device A priority value for calculating a priority value of each cache for a cache group constituted by caches having master and slave attributes among the respective caches included in the plurality of controllers by a predetermined calculation based on A calculation unit;
A cache attribute control unit that determines the attribute of each of the caches according to the calculated priority value, and changes the attribute of each of the caches to the determined attribute;
It is characterized by providing.

  Alternatively, this object can also be achieved by a controller of a disk array device including the cache control device described above or a disk array device.

  In order to achieve the same object, the cache control method according to the present invention is characterized by having the following configuration.

That is, the cache control method according to the present invention is:
Configuration information of a plurality of controllers that control the disk array device, load information that indicates an I / O load in an information processing device that issues an I / O request to the disk array device, and priority information that indicates a priority in the information processing device Based on a predetermined calculation, a cache group configured by caches having master and slave attributes among the caches included in the plurality of controllers is calculated, and a priority value of each cache is calculated.
In accordance with the calculated priority value, the attribute of each cache is determined, and the attribute of each cache is changed to the determined attribute.
It is characterized by that.

  This object is also achieved by a computer program for realizing the cache control device and the cache control method having the above-described configurations by a computer, and a readable storage medium in which the computer program is stored. .

  According to the present invention, it is possible to provide a cache control device and the like that can prevent the performance of a disk array device from deteriorating even when a state or information related to I / O processing changes dynamically. Can do.

It is a block diagram which shows the structure of the cache control apparatus in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement which the cache control apparatus in the 1st Embodiment of this invention performs. It is a block diagram which shows the structure of the controller group containing the cache control apparatus in the 2nd Embodiment of this invention. It is a figure which illustrates notionally the attribute of the cache before changing with the cache control apparatus in the 2nd Embodiment of this invention, and the connection relation of the controller and server apparatus containing the cache. It is a figure which illustrates concretely the priority value Z calculated by the priority value calculation part in the 2nd Embodiment of this invention (1st calculation). It is a figure which illustrates concretely the priority value Z calculated by the priority value calculation part in the 2nd Embodiment of this invention (2nd calculation). It is a figure which illustrates concretely the priority value Z calculated by the priority value calculation part in the 2nd Embodiment of this invention (3rd calculation). It is a figure which illustrates concretely the attribute of the cache determined by the cache attribute determination part in the 2nd Embodiment of this invention. It is a block diagram explaining illustratively the hardware constitutions of the information processor which can realize each embodiment concerning the present invention. It is a figure which illustrates notionally the composition of four controllers, and the attribute of the cache contained in four controllers. FIG. 11 is a sequence diagram illustrating the flow of processing in the disk array device when a controller including a cache master receives a write request from a server device. FIG. 11 is a sequence diagram illustrating a processing flow in the disk array device when a controller including a cache sub-slave receives a write request from a server device. FIG. 11 is a sequence diagram illustrating a processing flow in the disk array device when a controller including a cache slave receives a write request from a server device. FIG. 11 is a sequence diagram illustrating a processing flow in the disk array device when a controller including a cache sub-slave receives a write request from a server device.

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

<First Embodiment>
FIG. 1 is a block diagram showing the configuration of the cache control device 1 according to the first embodiment of the present invention.

  In FIG. 1, the cache control device 1 includes a priority value calculation unit 2 and a cache attribute control unit 3.

  More specifically, the priority value calculation unit 2 obtains, for example, configuration information of a plurality of controllers that control the disk array device, and performs a predetermined calculation based on the obtained configuration information, load information 101, and priority information 102. For a cache group, a cache priority value Z included in each controller is calculated for each predetermined time period. As described later, the priority value calculation unit 2 may perform the predetermined calculation for each cache group, for example. The priority value calculation unit 2 transmits the calculated priority value Z to the cache attribute control unit 3.

  In the present embodiment, the cache indicates, for example, a cache included in a controller constituting a generally known disk array device.

  The cache group indicates a redundant configuration using caches included in a plurality of controllers. The cache group is constituted by caches having attributes of the master and slave types among the caches included in the plurality of controllers.

  More specifically, the cache group includes a cache master that is used mainly when executing I / O processing, and a cache slave that is used when data held in the cache master is duplicated. In this embodiment, caches other than the cache master and the cache slave are referred to as cache sub-slave. The cache sub-slave is a cache that cannot be used as the cache master and the cache slave among the caches included in the plurality of controllers.

  The controller including the cache has a control unit that controls the I / O processing for the Rank. In the following description, for convenience of explanation, the control unit that mainly controls the I / O processing for the Rank is referred to as a Rank master, and the other control unit is referred to as a Rank slave (the same applies to the following embodiments). .

  The Rank represents a storage area (hereinafter, also simply referred to as “storage area”) in which physical storage devices such as a plurality of hard disk drives are logically configured in a predetermined unit.

  Note that as the technique for the priority value calculation unit 2 to obtain the controller configuration information, a general technique can be adopted at present. For this reason, in this embodiment, the detailed description regarding the technique which calculates | requires the structure information which concerns is abbreviate | omitted (hereinafter, the same also in each embodiment).

  The load information 101 is a load (i.e., I / O) in each server device (hereinafter also referred to as “information processing device”) that issues an I / O request to a Rank that is a control target associated with a cache group. O load) is included.

  The priority information 102 includes information indicating the priority in each server device that issues an I / O request to a Rank that is a control target associated with the cache group.

  Here, the priority is information set so that an I / O request issued from the server apparatus to the Rank can be preferentially executed.

  The configuration information includes information indicating the result of determining the redundant configuration of the cache whose priority value Z is to be calculated, and the attribute of the control unit that controls the I / O processing in the controller including the cache whose priority value Z is to be calculated. Information indicating a result of the determination (that is, whether or not the controller includes a Rank master or a Rank slave).

  More specifically, as an example, the information indicating the redundant configuration is included in another controller that is different from the controller in the same casing as the controller including the cache for which the priority value Z is calculated in the cache group. This is information indicating the result of determining the redundancy between the cache and the cache whose priority value Z is to be calculated.

  The cache attribute control unit 3 sets the cache attributes (master, slave and sub-slave) for each cache group according to the cache priority value Z calculated for each cache group received from the priority value calculation unit 2. At the same time, the cache attribute is changed based on the determination result.

  In the following description, the operation of the cache control device 1 in the present embodiment will be described more specifically.

  FIG. 2 is a flowchart showing operations performed by the cache control device 1 according to the first embodiment of the present invention. The operation procedure of the cache control device 1 will be described along the flowchart.

Step S1:
The priority value calculation unit 2 obtains the controller configuration information, and performs a predetermined calculation based on the obtained configuration information, the load information 101, and the priority information 102, for each cache group, the priority value of the cache included in each controller. Z is calculated. The priority value calculation unit 2 transmits the calculated priority value Z to the cache attribute control unit 3.

  More specifically, as an example, a method for calculating the priority value Z will be described here. In the present embodiment, the priority value calculation unit 2 calculates the priority value Z by, for example, the following equation (1).

  In equation (1), each parameter is as follows.

P: a cache group number that can identify a cache group including a cache whose priority value Z is to be calculated,
X: a controller number that can identify a controller including a cache whose priority value Z is to be calculated
M: Number of Ranks to be controlled associated with the cache group ^p ,
N: the number of server devices (the number of all server devices) that issues an I / O request to a Rank that is a control target associated with one or more cache groups including the cache group ^p ,
A _ki : the priority in the server device ^k that issues an I / O request to Rank ⁱ that is the control target associated with the cache group ^p ,
B _ki : I / O load in the server device ^k that issues an I / O request to Rank ⁱ that is a control target associated with the cache group ^p ,
· C _x: results in a cache group ^p, determines a cache included in a different other controllers controllers ^x that present in the same housing and controller ^x, redundancy cache made subject to calculation of priority values Z D _x : A value indicating the result of determining the attribute of the control unit that controls the I / O processing in the controller ^x .

More specifically, in equation (1), element A is the sum of priorities in all server apparatuses that issue I / O requests to all Ranks associated with the cache group ^p . Element B is the sum of loads (that is, I / O loads) in all server apparatuses that issue I / O requests to all Ranks associated with the cache group ^p .

Furthermore, C _x is the cache group ^p including a cache as a calculation target priority value Z, the same controller ^x of housing controllers ^x and another controller different (i.e., another controller) of cash contained in When the attribute is either the cache master or the cache slave, the value is “0”. On the other hand, when the attribute is not the cache master or the cache slave, the value is “1”. Here, and in another controller different controllers ^x of the same housing and the controller ^x, in the cache group ^p including a cache as a calculation target of priority values Z, physical DAC group including a controller ^x a (DAC housing) It is another controller to configure.

Thereby, the cache control device 1 can suppress the cache group ^{p from being} configured to include the cache master and the cache slave in the same casing as the controller ^x .

Further, D _x represents a master (Rank master) that is mainly controlled by a control unit that controls I / O processing in the controller ^x , and a value of D _x represents a slave (Rank slave). If it is not “1”, master or slave, the value is “0”.

  Α, β, and γ are predetermined parameters. For the predetermined parameters (α, β, γ), for example, a configuration arbitrarily determined by the user can be adopted.

Step S2:
The cache attribute control unit 3 includes a controller and a cache including a cache corresponding to the priority value Z indicating the largest value among the priority values Z of the respective caches calculated for each cache group received from the priority value calculation unit 2. Ask for a group.

  In the embodiment described above, for convenience of explanation, as an example, the cache attribute control unit 3 sets the priority value Z indicating the largest value among the priority values Z of the respective caches calculated for each cache group. The configuration for obtaining the controller and cache group including the corresponding cache has been described as an example.

  However, the embodiment according to the present invention is not limited to such a configuration. For example, the cache attribute control unit 3 is configured to obtain a controller and a cache group including a cache corresponding to the priority value Z indicating the smallest value from among the cache priority values Z calculated for each cache group. It may be adopted.

  In this case, the cache attribute control unit 3 can adopt a configuration in which the cache corresponding to the priority value Z indicating the smallest value is determined as the cache sub-slave. However, the present invention described using this embodiment as an example is not limited to the configuration described above (hereinafter, the same applies to each embodiment).

Step S3:
The cache attribute control unit 3 determines whether or not there is a cache whose attribute is already determined to be a master (that is, cache master) in the obtained cache group (that is, whether or not there is a cache).

“YES” in step S3:
When the cache attribute control unit 3 determines that there is a cache whose attribute is already determined as the cache master in the obtained cache group, and determines that there is a cache already determined as the cache master, the cache attribute control unit 3 performs the processing in step S5. Proceed to

“NO” in step S3:
If the cache attribute control unit 3 determines in the obtained cache group that there is no cache whose attribute has already been determined as the cache master, and determines that there is no cache already determined as the cache master, the process proceeds to step S4. Proceed to

Step S4:
The cache attribute control unit 3 determines the cache attribute included in the controller obtained in step S2 as a master (that is, cache master) in the obtained cache group. The cache attribute control unit 3 advances the process to step S7.

Step S5:
The cache attribute control unit 3 determines the attribute of the cache included in the controller obtained in step S2 as a slave (that is, a cache slave) in the obtained cache group.

Step S6:
In the obtained cache group, the cache attribute control unit 3 determines the attribute of the cache included in another controller different from the controller including the cache determined as the cache master and the cache slave as the sub slave (that is, the cache sub slave). That is, the cache attribute control unit 3 determines a cache attribute whose attribute is not determined as a sub slave.

Step S7:
The cache attribute control unit 3 determines the attribute of the cache included in the obtained controller as a sub slave in another cache group different from the obtained cache group.

Step S8:
The cache attribute control unit 3 determines whether or not all cache attributes have been determined for each of one or more cache groups including the obtained cache group.

“YES” in step S8:
As a result of determining whether or not all the cache attributes have been determined for each cache group, the cache attribute control unit 3 advances the process to step S10 when determining that the cache attribute has been determined.

“NO” in step S8:
If the cache attribute control unit 3 determines that all the cache attributes have been determined for each cache group and determines that the cache attribute has not been determined, the process proceeds to step S9. .

Step S9:
The priority value calculation unit 2 obtains the controller configuration information, and performs a predetermined calculation based on the obtained configuration information, load information 101, and priority information 102, for each cache group, from among the caches included in each controller. The priority value Z of the cache whose attribute is not determined is calculated. The priority value calculation unit 2 transmits the calculated priority value Z to the cache attribute control unit 3 and returns the process to step S2.

  In the above-described embodiment, for convenience of explanation, as an example, the priority value calculation unit 2 determines, for each cache group, caches whose attributes are not determined from the caches included in each controller in step S9. The configuration for calculating the priority value Z has been described as an example.

  However, the embodiment according to the present invention is not limited to such a configuration. The priority value calculation unit 2 may adopt a configuration for calculating the cache priority value Z included in each controller for each cache group described in step S1.

Step S10:
The cache attribute control unit 3 changes the cache attribute based on the determination result.

  In the above-described embodiment, as an example, for the sake of convenience of explanation, the cache control device 1 has been described by taking an example of a configuration in which the above-described processing is executed every predetermined time period. However, the embodiment according to the present invention is not limited to such a configuration. The cache control device 1 may employ a configuration in which a parameter indicating the time when the priority value Z is calculated is added to the priority value Z, and the above-described processing is executed according to the added time. As a result, the cache control device 1 can perform control so as not to execute the above-described processing when a long time has not elapsed since the cache attribute was changed.

  In addition, the priority value calculation unit 2 may calculate an increase / decrease value of the priority value Z, and may execute a process described above when the calculated increase / decrease value exceeds a predetermined threshold. Thereby, for example, when the I / O load included in the load information 101 greatly increases or decreases, the cache control device 1 can determine the optimal cache attribute.

  As described above, according to the cache control device 1 according to the present embodiment, it is possible to prevent the performance of the disk array device from deteriorating even when the state and information related to the I / O processing are dynamically changed. Can do. The reason is as described below.

  In other words, the cache control device 1 can determine an optimal cache attribute from a plurality of caches according to the state and information related to I / O processing, and can configure a cache group with the determined cache. is there.

  More specifically, the priority value calculation unit 2 of the cache control device 1 is predetermined based on load information 101, priority information 102, and controller configuration information between the server device and the disk array device having the cache control device 1, for example. The cache priority value Z is calculated by the above calculation. The cache attribute control unit 3 determines a cache attribute (master, slave, and sub-slave) according to the priority value Z calculated by the priority value calculation unit 2, and determines the cache attribute based on the determination result. This is because it can be changed. That is, the cache control device 1 dynamically changes the cache attributes between the server device and the disk array device according to the I / O load, priority, and disk array device configuration information. Because it can.

  Thereby, for example, the disk array device having the cache control device 1 can suppress deterioration in performance due to cache attributes (master, slave, and sub-slave).

  Further, for example, the user can connect the server device and the disk array device without worrying about the difference in performance due to the attributes of the cache constituting the disk array device. Further, even when a newly added server device is connected to the disk array device, the user does not need to review the connection between the server device and the disk array device.

<Second Embodiment>
Next, a second embodiment based on the cache control device 1 according to the first embodiment of the present invention described above will be described. In the following description, the characteristic part according to the present embodiment will be mainly described. At this time, the same reference numerals are assigned to the same configurations as those in the above-described embodiments, and duplicate descriptions are omitted.

  A cache control device 10 according to a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 3 is a block diagram showing a configuration of the controller group 20 including the cache control device 10 according to the second embodiment of the present invention.

  In the present embodiment, for convenience of explanation, as an example, the controller group 20 shown in FIG. 3 is a controller included in the disk array device. The controller group 20 includes a first controller 21 (controller # 0, a specific controller), a second controller 22 (controller # 1), a third controller 23 (controller # 2), and a fourth controller 24 (controller # 3). It shall have. In FIG. 3, it is assumed that the first controller 21 and the third controller 23 exist in the same casing. Further, it is assumed that the second controller 22 and the fourth controller 24 exist in the same casing. That is, the first controller 21 and the third controller 23 are included in the same physical DAC group (DAC housing). The second controller 22 and the fourth controller 24 are included in the same physical DAC group (DAC housing).

  In FIG. 3, the first controller 21 includes the cache control device 10. Further, the second controller 22 to the fourth controller 24 include the cache control device 10a.

  The cache control device 10 includes a priority value calculation unit 12, a monitoring unit 11, a cache attribute determination unit 13, a cache attribute change unit 14, and a setting unit 15.

  The cache control device 10a includes a priority value calculation unit 12, a monitoring unit 11, and a cache attribute change unit 14.

  The monitoring unit 11 monitors I / O requests issued from one or more server devices to one or more Ranks, and uses the priority and I / O for the server devices based on the I / O requests. Find the O load. As will be described later, the monitoring unit 11 may perform the priority and I / O load for each server device, for example. Furthermore, the monitoring unit 11 transmits the obtained priority and I / O load for each server device to the priority value calculation unit 12 as load information and priority information.

  More specifically, the monitoring unit 11 monitors an I / O request issued from each server device to the Rank over a predetermined time, and the priority set in the I / O request. You may obtain | require an average value as a priority of the said server apparatus.

  Incidentally, as the technology for the monitoring unit 11 to obtain the I / O load and the priority, a general technology can be adopted at present. For this reason, in this embodiment, a detailed description of the technique for obtaining the I / O load and priority is omitted (hereinafter, the same applies to each embodiment).

  The priority value calculation unit 12 obtains the controller configuration information, and performs a predetermined calculation on the basis of the obtained configuration information, load information 101 and priority information 102 for each cache group to the controller including the priority value calculation unit 12. The priority value Z of the included cache is calculated. The priority value calculation unit 12 transmits the priority value Z calculated for each cache group to the cache attribute determination unit 13.

  Next, the cache attribute determination unit 13 and the cache attribute change unit 14 correspond to the cache attribute control unit 3 described in the first embodiment. The cache attribute determination unit 13 executes the processing described in steps S2 to S8 shown in FIG. The cache attribute changing unit 14 executes the process described in step S10 illustrated in FIG.

  More specifically, the cache attribute determination unit 13 determines cache attributes (master, slave, and sub-slave) according to the priority value Z received from the priority value calculation unit 12, and the determination result is transmitted to the cache attribute change unit. 14 is transmitted.

  The cache attribute change unit 14 changes the cache attribute based on the determination result received from the cache attribute determination unit 13.

  For example, the setting unit 15 sets parameters used when the priority value calculation unit 12 calculates the priority value Z in accordance with a user operation. Further, the setting unit 15 changes the cache attribute in accordance with the user's operation.

  In the following description, the operation of the cache control device 10 in the present embodiment will be described more specifically.

  Here, for convenience of explanation, as an example, the cache control device 10 changes the attributes of the caches included in the four controllers of the first controller 21, the second controller 22, the third controller 23, and the fourth controller 24. To do.

  FIG. 4 is a diagram conceptually illustrating the attributes of the cache before being changed by the cache control device 10 according to the second embodiment of the present invention, and the connection relationship between the controller including the cache and the server device.

  In FIG. 4, the 0th cache group 41 (cache group # 0) includes a cache master 51 and a cache slave 52. A cache other than the cache master 51 and the cache slave 52 is a cache sub-slave 53 and a cache sub-slave 54. The first cache group 42 (cache group # 1) includes a cache master 55 and a cache slave 56. Caches other than the cache master 55 and the cache slave 56 are a cache sub slave 57 and a cache sub slave 58.

  It is assumed that the first server device 43, the second server device 44, the seventh server device 49, and the eighth server device 50 are connected to the first controller 21.

  The third server device 45 is connected to the second controller 22 and the third controller 23. The fourth server device 46 is connected to the second controller 22.

  It is assumed that the fifth server device 47 is connected to the fourth controller 24. The sixth server device 48 is connected to the third controller 23 and the fourth controller 24.

  The first server device 43, the sixth server device 48, and the eighth server device 50 issue an I / O request to Rank1. The second server device 44 issues an I / O request to Rank3.

  The third server device 45 issues an I / O request to Rank0. The fourth server device 46 issues an I / O request to Rank2. The fifth server device 47 issues an I / O request to Rank4. The seventh server device 49 issues an I / O request to the Rank 6.

  For convenience of explanation, the above-described configuration will be described as an example. However, the present invention described using this embodiment as an example is not limited to this configuration (the same applies to the following embodiments).

  The monitoring unit 11 of the first controller 21 to the fourth controller 24 transmits load information and priority information to the priority value calculation unit 12 of the first controller 21 to the fourth controller 24 for each predetermined time period. .

  In the following description, for convenience of explanation, here, the load information and the priority information transmitted from the monitoring unit 11 of the first controller 21 to the priority value calculation unit 12 of the first controller 21 are respectively referred to as the first load information. 101a and first priority information 102a. The load information and priority information transmitted from the monitoring unit 11 of the second controller 22 to the priority value calculation unit 12 of the second controller 22 are referred to as second load information 101b and second priority information 102b, respectively.

  The load information and priority information transmitted from the monitoring unit 11 of the third controller 23 to the priority value calculation unit 12 of the third controller 23 are referred to as third load information 101c and third priority information 102c. The load information and priority information transmitted from the monitoring unit 11 of the fourth controller 24 to the priority value calculation unit 12 of the fourth controller 24 are referred to as fourth load information 101d and fourth priority information 102d.

  The priority value calculation unit 12 of the first controller 21 to the fourth controller 24 obtains the configuration information of the first controller 21 to the fourth controller 24 and the obtained configuration information and load information 101 (101a, 101b, 101c, and 101d). The cache priority value Z included in the controller is calculated for each cache group by a predetermined calculation based on the priority information 102 (102a, 102b, 102c and 102d).

  More specifically, as an example, the priority value calculation unit 12 of the first controller 21 obtains the configuration information of the first controller 21 and performs a predetermined calculation based on the obtained configuration information, load information 101a, and priority information 102a. The priority value Z of the cache included in the first controller 21 is calculated for each cache group.

  More specifically, here, a case where the priority value Z of the cache included in the first controller 21 configuring the first cache group 42 is calculated based on the connection diagram of the server apparatus illustrated in FIG. 4 will be described.

  In FIG. 4, a first server device 43, a second server device 44, a seventh server device 49, and an eighth server device 50 are connected to the first controller 21.

  The first cache group 42 executes an I / O process for odd-numbered Ranks. Therefore, in the first cache group 42, the server devices that are the targets when calculating the cache priority value Z included in the first controller 21 are the first server device 43, the second server device 44, and the eighth server device 50. It is.

  The priority value calculation unit 12 of the first controller 21 obtains the cache priority value Z by the following equation (2).

  The priority value calculation unit 12 of the first controller 21 to the fourth controller 24 transmits the calculated priority value Z to the cache attribute determination unit 13 of the first controller 21.

  FIG. 5 (FIGS. 5A, 5B, and 5C) is a diagram specifically illustrating the priority value Z calculated by the priority value calculation unit 12 in the second embodiment of the present invention.

  In FIG. 5 (FIGS. 5A, 5B, and 5C), the first column represents the name of the controller (controller name) that includes the caches that make up the cache group. The second and third columns represent the cache priority value Z calculated for each cache group by the priority value calculation unit 12 or the cache attribute determined by the cache attribute determination unit 13.

  FIG. 5A is a diagram specifically illustrating the priority value Z calculated by the priority value calculation unit 12 in the second embodiment of the present invention (first calculation).

  In FIG. 5A, the priority value Z is the value with the highest cache priority value Z “80” included in the first controller 21 configuring the first cache group 42.

  Therefore, the cache attribute determination unit 13 includes a controller including a cache corresponding to the priority value Z indicating the largest value among the priority values Z received from the priority value calculation units 12 of the first controller 21 to the fourth controller 24. Ask for a cash group.

  Here, the cache attribute determination unit 13 obtains the first controller 21 and the first cache group 42.

  Further, the cache attribute determination unit 13 determines whether or not there is a cache whose attribute has already been determined for the cache master in the obtained first cache group 42.

  Here, in the first cache group 42, there is no cache whose attribute has already been determined as the cache master. Therefore, the cache attribute determination unit 13 determines the attribute of the cache included in the first controller 21 as the first cache group 42. To determine the cache master.

  Further, the cache attribute determination unit 13 determines the cache attribute included in the first controller 21 as a cache sub-slave in another 0th cache group 41 different from the obtained first cache group 42.

  The cache attribute determination unit 13 determines whether or not all the cache attributes included in each controller have been determined for each cache group (the zeroth cache group 41 and the first cache group 42), and as a result, the cache attribute Is determined to be undecided.

  The priority value calculation unit 12 of the first controller 21 to the fourth controller 24 obtains the configuration information of the first controller 21 to the fourth controller 24 and the obtained configuration information and load information 101 (101a, 101b, 101c, and 101d). And the priority value Z of the cache included in the controller for which the cache attribute included in the cache group is not determined for each cache group by a predetermined calculation based on the priority information 102 (102a, 102b, 102c and 102d). calculate. The priority value calculation unit 12 transmits the calculated priority value Z to the cache attribute control unit 3.

  FIG. 5B is a diagram specifically illustrating the priority value Z calculated by the priority value calculation unit 12 in the second embodiment of the present invention (second calculation).

  In FIG. 5B, the priority value Z is the value with the highest cache priority value Z “55” included in the second controller 22 configuring the 0th cache group 41.

  Therefore, the cache attribute determination unit 13 includes a cache corresponding to the priority value Z indicating the largest value among the priority values Z received from the priority value calculation units 12 of the first controller 21 to the fourth controller 24. The controller 22 and the 0th cache group 41 are obtained.

  Further, the cache attribute determination unit 13 determines whether or not there is a cache whose attribute has already been determined for the cache master in the obtained 0th cache group 41.

  Here, in the 0th cache group 41, since there is no cache whose attribute has already been determined as the cache master, the cache attribute determination unit 13 determines the cache attribute included in the obtained second controller 22 as the 0th cache group 41. To determine the cache master.

  The cache attribute determination unit 13 determines the cache attribute included in the second controller 22 as a cache sub-slave in another first cache group 42 different from the obtained zeroth cache group 41.

  The cache attribute control unit 3 determines whether or not all the cache attributes included in each controller are determined for each cache group (the 0th cache group 41 and the first cache group 42), and as a result, determines the cache attributes. Is determined to be undecided.

  The priority value calculation unit 12 of the first controller 21 to the fourth controller 24 obtains the configuration information of the first controller 21 to the fourth controller 24 and the obtained configuration information and load information 101 (101a, 101b, 101c, and 101d). And the priority value Z of the cache included in the controller for which the cache attribute included in the cache group is not determined for each cache group by a predetermined calculation based on the priority information 102 (102a, 102b, 102c and 102d). calculate. The priority value calculation unit 12 transmits the calculated priority value Z to the cache attribute control unit 3.

  FIG. 5C is a diagram specifically illustrating the priority value Z calculated by the priority value calculation unit 12 in the second embodiment of the present invention (third calculation).

  In FIG. 5C, the priority value Z is the value with the highest cache priority value Z “30” included in the third controller 23 configuring the 0th cache group 41.

  Therefore, the cache attribute determination unit 13 includes a cache corresponding to the priority value Z indicating the largest value among the priority values Z received from the priority value calculation units 12 of the first controller 21 to the fourth controller 24. The controller 23 and the 0th cache group 41 are obtained.

  Further, the cache attribute determination unit 13 determines whether or not there is a cache whose attribute has already been determined for the cache master in the obtained 0th cache group 41.

  Here, in the 0th cache group 41, since there is a cache whose attribute has already been determined as the cache master, the cache attribute determination unit 13 determines the cache attribute included in the obtained third controller 23 as a cache slave. .

  The cache attribute determination unit 13 determines the cache attribute included in the third controller 23 as a cache sub-slave in another first cache group 42 different from the obtained zeroth cache group 41.

  In this way, the cache control device 10 repeats the above-described processing until the cache attributes included in all the controllers are determined for each cache group.

  As a result of determining whether or not all cache attributes included in the controller have been determined for each cache group, the cache attribute determination unit 13 determines that all cache attributes have been determined. Is transmitted to the cache attribute changing unit 14.

  The cache attribute change unit 14 changes the cache attribute based on the determination result received from the cache attribute determination unit 13.

  FIG. 6 is a diagram specifically illustrating the cache attributes determined by the cache attribute determination unit 13 according to the second embodiment of the present invention.

  In FIG. 6, the first column represents the name of the controller (controller name) that includes the caches that make up the cache group. The second and third columns represent cache attributes determined by the cache attribute determination unit 13.

  In the above-described embodiment, for the sake of convenience of explanation, the cache controller 10 including the cache attribute determination unit 13 is described as an example of the configuration of the first controller 21. However, the embodiment according to the present invention is not limited to such a configuration. The cache control device 10 may employ a configuration included in any of the first controller 21 to the fourth controller 24.

  Further, in the present embodiment described above, for the sake of convenience of explanation, as an example, the cache control device 10a has been described by taking a configuration that does not include the setting unit 15 and the cache attribute determination unit 13. However, the embodiment according to the present invention is not limited to such a configuration. The cache control device 10a may adopt a configuration including the setting unit 15 and the cache attribute determination unit 13.

  In this case, the cache attribute may be configured such that any one of the one or more cache attribute determination units 13 determines the cache attribute.

  Further, in the present embodiment described above, for convenience of explanation, the operation when the cache control device 10 is applied to a disk array device including four controllers has been described as an example. However, the embodiment according to the present invention is not limited to such a configuration. The cache control device 10 may be applied to a disk array device including four or more, for example, eight controllers.

  In that case, the cache control device 10 can control the cache by preparing four cache groups and dividing the Rank associated with the cache group by a multiple of 4.

  Further, in the above-described embodiment, for the sake of convenience of explanation, the monitoring unit 11 is described as an example of a configuration for obtaining the I / O load and the priority. However, the embodiment according to the present invention is not limited to such a configuration. For example, when the I / O load or priority exceeds a predetermined threshold, the monitoring unit 11 determines that the I / O request is from a high load or high priority server device, and A configuration in which values are transmitted to the priority value calculation unit 12 as load information 101 and priority information 102 may be employed.

  As described above, according to the cache control device 10 according to the present embodiment, the effects described in the embodiments can be enjoyed, and further, the status and information regarding I / O processing between the server device and the disk array device. It is possible to prevent the performance of the disk array device from degrading more quickly even if the disk is dynamically changed.

  This is because the cache control device 10 (10, 10a) is provided for each controller. Therefore, the priority value calculation unit 12 of the cache control device 10 can more quickly calculate the cache priority value Z included in the controller for each cache group.

(Hardware configuration example)
Each unit shown in the drawings in the embodiment described above can be regarded as a function (processing) unit (software module) of a software program. Each of these software modules may be realized by dedicated hardware. However, the division of each part shown in these drawings is a configuration for convenience of explanation, and various configurations can be assumed in mounting. An example of the hardware environment in this case will be described with reference to FIG.

  FIG. 7 is a diagram illustrating an exemplary configuration of an information processing device 300 (computer) that can execute the terminal identification device according to the exemplary embodiment of the present invention. That is, FIG. 7 shows a computer (information processing device) such as a server capable of realizing the cache control device 1 shown in FIG. 1 or the cache control device 10 shown in FIG. The hardware environment which can implement | achieve each function in embodiment mentioned above is shown.

  The information processing apparatus 300 shown in FIG. 7 includes a CPU (Central_Processing_Unit) 301, a ROM (Read_Only_Memory) 302, a RAM (Random_Access_Memory) 303, a hard disk 304 (storage device), and a communication interface (Interface: hereinafter “I”). / F ”) 305, and a reader / writer 308 capable of reading and writing data stored in a storage medium 307 such as a CD-ROM (Compact_Disc_Read_Only_Memory), and these components are connected via a bus 306 (communication line). It is a general computer.

  The present invention described using the above-described embodiment as an example is based on the block configuration diagram (FIGS. 1 and 3) or the flowchart (FIG. 2) referred to in the description of the information processing apparatus 300 shown in FIG. This is achieved by supplying a computer program capable of realizing the function and then reading the computer program to the CPU 301 of the hardware and executing it. Further, the computer program supplied to the apparatus may be stored in a nonvolatile storage device such as a readable / writable temporary storage memory (RAM 303) or a hard disk 304.

  In the above case, the computer program can be supplied to the hardware by a method of installing the computer program via various storage media 307 such as a CD-ROM or a communication line such as the Internet. Currently, a general procedure can be adopted, such as a method of downloading from the outside. In such a case, the present invention can be regarded as being configured by a code constituting the computer program or a storage medium storing the code.

DESCRIPTION OF SYMBOLS 1 Cache control apparatus 2 Priority value calculation part 3 Cache attribute control part 10 Cache control apparatus 10a Cache control apparatus 11 Monitoring part 12 Priority value calculation part 13 Cache attribute determination part 14 Cache attribute change part 15 Setting part 20 Controller group 21 1st controller 22 2nd controller 23 3rd controller 24 4th controller 41 0th cache group 42 1st cache group 43 1st server device 44 2nd server device 45 3rd server device 46 4th server device 47 5th server device 48 6th Server device 49 Seventh server device 50 Eighth server device 51 Cache master 52 Cache slave 53 Cache sub-slave 54 Cache sub-slave 55 Cache master 56 Cache slave 57 Cache Sub slave 58 Cache sub slave 101 Load information 101a First load information 101b Second load information 101c Third load information 101d Fourth load information 102 Priority information 102a First priority information 102b Second priority information 102c Third priority Degree information 102d Fourth priority information 201 First physical DAC group 202 Second physical DAC group 203 First logical DAC group 204 Second logical DAC group 205 First controller 206 Second controller 207 Third controller 208 Fourth controller 209 First 1 cache 210 2nd cache 211 3rd cache 212 4th cache 300 Information processing device 301 CPU
302 ROM
303 RAM
304 Hard Disk 305 Communication Interface 306 Bus 307 Storage Medium 308 Reader / Writer

Claims (10)

Configuration information of a plurality of controllers that control the disk array device, load information that indicates an I / O load in an information processing device that issues an I / O request to the disk array device, and priority information that indicates a priority in the information processing device A priority value for calculating a priority value of each cache for a cache group constituted by caches having master and slave attributes among the respective caches included in the plurality of controllers by a predetermined calculation based on A calculation unit;
A cache attribute control unit that determines the attribute of each of the caches according to the calculated priority value, and changes the attribute of each of the caches to the determined attribute;
A cache control apparatus comprising: The cache attribute control unit, as a series of processing,
From the calculated cache priority values, a controller including a cache corresponding to the priority value indicating the largest value and the cache group are obtained,
In the obtained cache group, the cache attribute included in the obtained controller is determined as either a master or a slave according to the result of determining whether or not there is a cache whose attribute is already determined as a master, When the cache attribute is determined to be a slave, the cache attribute that is not determined among the caches included in another controller different from the obtained controller is determined to be a sub-slave,
2. The cache control apparatus according to claim 1, wherein an attribute of a cache included in the obtained controller is determined as a sub slave in another cache group different from the obtained cache group. The cache attribute control unit
For each of the cache groups, determine whether or not the respective cache attribute has been determined, and when determining that the respective cache attribute has not been determined, execute the series of processing,
The priority value calculation unit
When it is determined by the cache attribute control unit that the attribute of each cache has not been determined, for each cache group, by the predetermined calculation based on the configuration information, the load information, and the priority information, The cache control apparatus according to claim 2, wherein a priority value of a cache whose attribute is not determined is calculated from each of the caches. The configuration information is
Information indicating the result of determining the redundant configuration of the cache that is the priority value calculation target, and the result of determining the attribute of the control unit that controls the I / O processing in the controller including the cache that is the priority value calculation target The cache control apparatus according to claim 1, further comprising: information to be displayed. The load information is
The information indicating the I / O load in each information processing apparatus that issues an I / O request to a storage area that is a control target associated with the cache group. 5. The cache control device according to any one of 4. The priority information is:
6. The cache control device according to claim 1, further comprising information indicating the priority in each of the information processing devices.   A controller of a disk array device comprising the cache control device according to any one of claims 1 to 6. A disk array device comprising a plurality of controllers that execute I / O processing in response to an I / O request from one or more information processing devices,
A specific controller among the plurality of controllers is
The I / O request issued from the information processing apparatus is monitored, the priority and I / O load are obtained for the information processing apparatus based on the I / O request, and the obtained priority and I A monitoring unit that transmits / O load as priority information and load information;
A cache group configured by caches having master and slave attributes among the respective caches included in the plurality of controllers by a predetermined calculation based on the configuration information of the specific controller, the load information, and the priority information. A priority value calculation unit that calculates a priority value of a cache included in the specific controller,
A cache attribute determination unit that determines an attribute of each of the caches according to a priority value calculated by the priority value calculation unit included in the plurality of controllers;
A cache attribute changing unit that changes the attribute of each cache to the determined attribute for the cache group;
Other controllers different from the specific controller are:
The monitoring unit;
A priority value calculation unit that calculates the priority value of the cache included in the different other controller for the cache group by a predetermined calculation based on the configuration information of the different controller, the load information, and the priority information. When,
The cache attribute changing unit;
A disk array device comprising: Configuration information of a plurality of controllers that control the disk array device, load information that indicates an I / O load in an information processing device that issues an I / O request to the disk array device, and priority information that indicates a priority in the information processing device Based on a predetermined calculation, a cache group configured by caches having master and slave attributes among the caches included in the plurality of controllers is calculated, and a priority value of each cache is calculated.
In accordance with the calculated priority value, the attribute of each cache is determined, and the attribute of each cache is changed to the determined attribute.
And a cache control method. Configuration information of a plurality of controllers that control the disk array device, load information that indicates an I / O load in an information processing device that issues an I / O request to the disk array device, and priority information that indicates a priority in the information processing device A function for calculating a priority value of each cache for a cache group configured by caches having master and slave attributes among the respective caches included in the plurality of controllers by a predetermined calculation based on ,
A function of determining the attribute of each of the caches according to the calculated priority value, and changing the attribute of each of the caches to the determined attribute;
A computer program characterized in that a computer is realized.

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