The system generally comprises one or more clients 1 that access data, storage 5 (file server, NAS (Network Attached Storage), etc.) that have multiple storage areas 5-A, 5-B, . . . , 5-C in which data is stored, an ILM device 2 that manages the data arrangement of the storage 5 by means of ILM (Information Lifecycle Management), a data migration execution unit 3 that migrates data among storage areas responsive to an instruction from the ILM device 2, an ILM device management terminal 4 used to manage or change the settings of the ILM device 2, and a network 6. Although the ILM device management terminal 4 is connected to the ILM device 2 via the network 6 in
According to the present invention, the ILM device 2 stores and manages a service level (Service Level Agreement; hereinafter termed SLA) that is a service level guaranteed to data by a storage area, checks whether or not the SLA of a storage area, where data is stored, satisfies the required Service Level Object (hereinafter termed SLO) assigned to the data, and controls the data arrangement processing so that the management requirements for storing data in a storage area having an SLA, which satisfies the SLO, are satisfied. If the SLA of a storage area where data is stored does not satisfies the SLO of the data, the ILM device 2 selects a storage area, which satisfies the SLO of the data, from the multiple storage areas 5-A, 5-B, . . . , 5-C and stores the data in the selected storage area.
In one example of the present invention, if one storage area contains data whose SLO may not be satisfied, the ILM device 2 checks whether or not the SLO is satisfied in the storage area where the data is stored, based on the SLO of the data and the SLA of the storage area. If the checking result indicates that the SLO is not satisfied, the ILM device 2 determines another storage area having an SLA corresponding to the SLO of the data and stores the data in the determined storage area. In this case, it is also possible to cause the data migration execution unit 3, which migrates data between storage areas, to move the data from the storage area described above to the determined another storage area.
In one example of the present invention, if the data migration execution unit 3 migrates data between storage areas and, as a result, other data cannot be migrated, the ILM device 2 does not cancel the migration of the data. Instead, the ILM device 2 carries over the solution of the problem that the SLO of the other data, which cannot be migrated, is not satisfied to the next and the subsequent data arrangement processing (ILM processing).
In one example of the present invention, if the location of data is changed to satisfy the SLO and, as a result, the free area size becomes equal to or lower than a predetermined value in a storage area, the ILM device 2 migrates data from the storage area to another storage area within a range, in which the SLO is satisfied, to reserve a free area.
In one example of the present invention, the ILM device 2 checks whether or not the SLO is within a range of the SLA guaranteed by the storage area, in which data is stored, for at least one of the following data: data created after the previous data arrangement processing (ILM processing), data whose SLO value requested by the data is changed, data stored in a storage area whose SLA is changed, and data whose SLO was not satisfied in the previous data arrangement processing.
In one example of the present invention, if there are multiple storage areas having an SLA satisfying the SLO of data, it is possible that the ILM device 2 calculates a score based on the difference in value between the SLA of the storage area and the SLO of the data for selecting a minimum-score storage area as the migration destination.
For example,
Score=Σ|(SLA parameter of storage area where data is stored)−(SLO parameter) (1)
If the SLA of a storage area where data is stored has four attributes, SLA=(p1, p2, p3, p4), and the SLO of data is SLO=(q1, q2, q3, q4), then the scores is given by the following expression.
Score==Σi=14|pi−qi|
If there are multiple candidates for the migration destination storage area, the minimum-score (that is, minimum distance) storage area is selected. The score is not limited by the distance but may also be calculated by the following expression.
Although not limited thereto, the indexes such as encryption, backup characteristics, redundancy, and performance are used as SLO attribute parameters.
It is also possible that the SLO has two types of values, that is, a target value that is a parameter required to be satisfied as much as possible and a parameter must value (MUST attribute) that must always be satisfied, to allow the ILM device 2 to select a storage area satisfying the parameter must value. For example, if the SLO of data is SLO=(q1, q2, q3, q4) and the attribute q1 of the attribute of the first term is the MUST attribute, it is assumed that p1 in SLA=(p1, p2, p3, p4) satisfies qi.
It is also possible that the SLO has two types of parameter values, that is, an upper limit value and/or a lower limit value, which can be assigned to a parameter, to allow the ILM device 2 to process the upper limit value and the lower limit value separately in the processing. For example, if the parameter value of 1 corresponds to WORM (Write Once Read Many) for the WORM attribute of the SLO parameter and if a storage area having an SLA where the WORM attribute parameter value is 0 or larger is selected for data having an SLO where WORM attribute parameter value is 0 and the data is stored in that storage area, an inconvenient condition occurs in which the data can be read but cannot be written. In this case, the upper limit value and the lower limit value of the SLO parameter are separated. The lower limit value of the WORM attribute parameter value is set to 1 and is separated from the WORM attribute parameter value of 0. Data having the WORM attribute parameter value of 0 is not stored in a storage area having the WORM attribute parameter value of 1 or larger.
It is also possible that, if the time required for the data arrangement processing (ILM processing) exceeds a predetermined time, the ILM device 2 suspends the processing at that point in time by completing the processing prematurely, migrates the data for which the processing has been completed up to that time, and carries over the processing of the data, which remains unprocessed because of the suspension, to the next and subsequent data arrangement processing.
It is possible to inhibit the ILM device 2 from migrating data, which has been migrated to another storage area by the data migration execution unit 3, to some other storage area during a predetermined period. When the present invention is applied to an enterprise system where the execution cycle of the data arrangement processing by the ILM device 2 is once a day (for example, when the business ends) and the predetermined period described above (during which data cannot be migrated) is two or three days, the data migrated to another storage area in the immediately preceding ILM processing is inhibited from being migrated, though not limited thereto, to some other storage area in the current or the current and the next ILM processing. Inhibiting the data migration during a predetermined period in this way prevents data from being migrated frequently when an abnormality occurs during the ILM processing. It is of course possible that the data migration inhibition period may be set freely in accordance with the system.
In addition, it is also possible that the ILM device 2 checks data in a predetermined storage area whether the data can be migrated to an area having an SLA better than that of the current area and, if so, migrates the data to that area. That is, the ILM device 2 may manage the data arrangement based on an SLA on an area basis in a storage area.
It is also possible that the ILM device 2 checks entire pieces of data in a predetermined storage area to search for an area, which has an SLA satisfying the SLO, from an area not included in the predetermined storage area.
When the storage 5 including multiple storage areas 5-A, 5-B, . . . , and 5-C is installed for use in HSM (Hierarchical Storage Management) in one example of the present invention, the data migration means provided in the HSM implementation environment is used as the data migration execution unit 3.
In the present invention, a policy for migrating data may be variably set and generated so that the SLO of data is satisfied by the SLA of a storage area where the data is stored.
Although the ILM device 2 is connected, not via the network 6, but directly to the data migration execution unit 3 in the system configuration shown
Although the ILM device 2 is configured as a server of the client 1, the present invention is not limited to such configuration. For example, the ILM device 2 and the data migration execution unit 3 may be integrated into one module that is installed in an intermediate device (not shown) between the storage 5 and the network 6.
The data management information recording unit 21 stores the following information on the data stored in the storage 5:
The storage management information recording unit 22 stores the following information on each storage area that is managed:
The ILM execution unit 23, which is started by an operation instruction issued from the ILM device control unit 24, calculates a arrangement that satisfies the SLO for implementing the ILM-based data management and sends the calculated result to the data migration execution unit 3.
The ILM device control unit 24
In addition, the ILM device control unit 24
It is of course possible that the ILM execution unit 23 and the ILM device control unit 24 are implemented by a program running on the computer constituting the ILM device 2.
Next, the following describes the configuration of the ILM execution unit 23 in
During the operation, the ILM execution unit 23 uses the flags and information, described below, that are stored in the data management information recording unit 21 and the storage management information recording unit 22.
The data management information recording unit 21 stores flags FL1 that are set when there is a possibility that the SLO of data is not satisfied, one flag for each piece of data stored in the storage 5.
Data indicated by this flag that there is a possibility that the SLO is not satisfied is one of the following:
The data management information recording unit 21 also stores information FL21 and FL22, one set of FL21 and FL22 for each piece of data stored in the storage 5. The information FL21 and FL22 indicate when the SLO of the data was last checked by the ILM device 2, respectively, in processing steps S1 and S2 of the ILM device 2 shown in
On the other hand, the storage management information recording unit 22 stores flags FL3, one for each storage area included in the storage 5. The flag FL3 is set when the SLA parameter of a storage area is changed after the ILM device 2 performed the ILM processing last.
The SLO checking/data migration determination unit 231 checks if each managed storage area included in the storage 5 satisfies the SLO of the data, determines the arrangement and the migration destination storage area best suited to the data based on the checking and, if the data must be migrated, sends a data migration instruction to the data migration execution unit 3.
The SLO checking/data migration determination unit 231 sends an operation start/end notification to the ILM device control unit 24. Conversely, when an operation interrupt instruction is received from the ILM device control unit 24, the SLO checking/data migration determination unit 231 interrupts the processing.
In addition, when the possibility that the SLO of data is not satisfied is gone, the SLO checking/data migration determination unit 231 clears the flag FL1. As described above, this FL1 is a flag stored in the data management information recording unit 21 to indicate that there is a possibility that the SLO of the data is not satisfied.
When data is processed in processing step S1 of the ILM device 2 shown in
If the flag FL3 is set to indicate that the SLA of the storage 5 is changed after the ILM device 2 performed the ILM processing last, the SLO checking/data migration determination unit 231 clears the flag FL3 when the processing is terminated.
If the free area size of a storage area in the storage 5 is insufficient, the free area size adjustment/data migration determination unit 232 checks whether the SLO of the data is satisfied if the data stored in that storage area is migrated to another storage area.
If the checking result indicates that the SLO of the data is satisfied and if the free area size of the data migration destination is not insufficient after the migration and, therefore, the data can be migrated to that another storage area, the free area size adjustment/data migration determination unit 232 instructs the data migration execution unit 3 to move the data to that another storage to which the data can be migrated.
The free area size adjustment/data migration determination unit 232 sends an operation start/end notification to the ILM device control unit 24. Conversely, when an operation interrupt instruction is received from the ILM device control unit 24, the free area size adjustment/data migration determination unit 232 interrupts the processing.
In addition, when the possibility that the SLO of data is not satisfied is gone, the free area size adjustment/data migration determination unit 232 clears the flag FL1 that is stored in the data management information recording unit 21. As described above, the FL1 is a flag indicating that there is a possibility that the SLO of the data is not satisfied.
Furthermore, when data is processed in processing step S2 (see
Next, the following describes the detailed configuration of the ILM device control unit 24 in
The storage free area size acquisition unit 241 obtains the free area sizes of the storage areas from the storage 5 via the network 6 and stores the values in the storage management information recording unit 22.
The storage free area size acquisition unit 241 suspends and resumes the storage of information into the storage management information recording unit 22 responsive to an instruction from the ILM execution control unit 246.
The access log generation unit 242 monitors the network 6 to generate the access history information on access from the client 1 to the data stored in the storage 5. The information on the generated access log and the storage area load is stored in the access log storage unit 243.
The access log storage unit 243 stores the access log, generated by the access log generation unit 242 in the ILM device control unit 24, and supplies the stored access log to the access log analysis unit 244 responsive to a request issued from that unit.
The access log analysis unit 244 reads the access log on the data, which is stored in the storage 5 of the client 1, from the access log storage unit 243 and analyzes the access log. The access log analysis unit 244 detects the creation of data in, and the deletion of data from, the storage 5 or detects a change in the size of data stored in the storage 5, and stores the detection result in the data management information recording unit 21 and the storage management information recording unit 22. In addition, responsive to an instruction from the ILM execution control unit 246, the access log analysis unit 244 suspends and resumes of storage of information into the data management information recording unit 21.
The ILM device management I/F 245 processes:
When the SLO of data stored in the storage 5 is changed, the flag FL1 is set because there is a possibility that the SLO is not satisfied when the SLO is changed.
When the SLA of a storage area included in the storage 5 is changed, the flag FL3, which indicates that the SLA of the storage area is changed, is set.
The ILM execution control unit 246 controls the operation of the ILM execution unit 23 to manage the operation of the whole ILM device 2.
The ILM execution control unit 246 receives an instruction from the ILM device management I/F 245 to start or stop the operation of the ILM execution unit 23.
According to the present invention, the ILM device control unit 24 of the ILM device 2 constantly performs the following operation.
The access log generation unit 242 included in the ILM device control unit 24 monitors the network 6 to detect access from the client 1 to the data in the storage 5 and generates an access log.
The access log generated by the access log generation unit 242 is recorded in the access log storage unit 243, and the access log analysis unit 244 analyzes the access log.
From the access log, the access log analysis unit 244 extracts information on
For newly created data, the following is set in the data management information recording unit 21.
The storage free area size acquisition unit 241 acquires a change in the size of the free area of the storage 5 and reflects the acquired information in the storage management information recording unit 22.
In addition, the ILM device management I/F 245 continuously accepts an instruction to change the setting and an instruction to operate the ILM processing from the ILM device management terminal 4.
A setting change instruction accepted by the ILM device management I/F 245 is reflected in the data management information recording unit 21 and the storage management information recording unit 22, and an ILM processing operation instruction is passed to the ILM execution control unit 246.
When the SLO of data is changed, the flag FL1, stored in the data management information recording unit 21, is set to indicate that there is a possibility that the SLO of the data is changed after the ILM device 2 performed the ILM processing last. When the SLA of a storage area is changed, the flag FL3, stored in the storage management information recording unit 22, is set to indicate that the SLA of the storage area is changed after the ILM device 2 performed the ILM processing last.
In addition, the ILM device management I/F 245 accepts the information (initial value of the SLO, the threshold for checking whether or not the free area size is insufficient) about newly created data from the ILM device management terminal 4, and reflects those values in the data management information recording unit 21 and the storage management information recording unit 22.
The ILM device 2 starts the ILM processing when the ILM device 2 receives an ILM processing start instruction from the ILM device management terminal 4.
More specifically, the ILM device management I/F 245 receives the ILM processing start instruction and sends the received ILM processing start instruction to the ILM execution control unit 246.
The ILM execution control unit 246 invokes the SLO checking/data migration determination unit 231 and the free area size adjustment/data migration determination unit 232 of the ILM execution unit 23 according to the operation sequence described below. At the same time, the ILM execution control unit 246 sends an instruction to the storage free area size acquisition unit 241 and the access log analysis unit 244 to stop the update of the information in the storage management information recording unit 22 and the data management information recording unit 21.
Next, the ILM execution control unit 246 invokes the SLO checking/data migration determination unit 231 to perform the following operation.
The ILM device 2 checks data created after the previous ILM processing, data whose SLO is changed, or data stored in a storage area whose SLA is changed, whether the SLO is satisfied in the storage area in which the data is stored. To do so, the SLO checking/data migration determination unit 231, included in the ILM execution unit 23, reads the SLO of the data from the data management information recording unit 21, and the SLA of the storage area, in which the data is currently stored, from the storage management information recording unit 22, and checks if the SLA satisfies the SLO (step S101).
In addition, for data whose SLO is not satisfied in the checking in the immediately preceding step S101 (NO in step S102), the SLO checking/data migration determination unit 231 compares the SLO with the SLA value (indicating the guaranteed service level) of all storage areas in the storage 5, and selects a storage area, whose SLA satisfies the SLO of the data, as the data migration destination. When the data migration destination is determined, the SLO checking/data migration determination unit 231 instructs the data migration execution unit 3 to move the data. In response to the instruction, the data migration execution unit 3 migrates the data to the storage area selected as the migration destination (S103).
After executing the processing steps S101 to S103, the SLO checking/data migration determination unit 231 terminates the operation.
Note that the data migration between storage areas as a result of the execution of the steps to the step S103 may create the possibility of an insufficient free area size in the storage area.
After the operation of the SLO checking/data migration determination unit 231 described above is terminated, the ILM execution control unit 246 starts the free area size adjustment/data migration determination unit 232 and executes the following processing steps to solve the problem of the insufficient free area size in the storage areas.
The ILM device 2 causes the free area size adjustment/data migration determination unit 232, included in the ILM execution unit 23, to acquire from the storage management information recording unit 22 the free area size in each storage area included in the storage 5 and the free area size threshold used to determine that the free area size in the storage area is insufficient.
For each storage area, the free area size adjustment/data migration determination unit 232 compares the free area size threshold of the storage area, used to determine if the free area size is insufficient, with the actual free area size and, if the comparison result indicates that the free area size is insufficient, executes the following processing steps to solve the problem of the insufficient free area size of the storage area.
To solve the problem of the insufficient free area size in each storage area, the free area size adjustment/data migration determination unit 232, included in the ILM execution unit 23, reads the data stored in a storage area whose free area size is insufficient, as well as the SLO of the data, from the data management information recording unit 21. The free area size adjustment/data migration determination unit 232 also reads the SLA of each storage area included in the storage 5 and its current free area size, as well as the threshold used to determine that the free area size of the storage area is insufficient, from the storage management information recording unit 22.
If, other than the storage area in which the data is currently stored, there is a storage area which satisfies the SLO of the data and if the free area size of that area is not determined insufficient even after the data is migrated thereto, the free area size adjustment/data migration determination unit 232 sends an instruction to the data migration execution unit 3 to move the data to that storage area (step S2).
After step S2 described above is terminated, the operation of the free area size adjustment/data migration determination unit 232 is terminated.
When the ILM operation of the ILM device is terminated, the ILM execution control unit 246 instructs the storage free area size acquisition unit 241 and the access log analysis unit 244 to restart the updating of information in the storage management information recording unit 22 and the data management information recording unit 21.
The ILM execution unit 23 included in the ILM device 2 checks if the storage 5 still stores data whose SLO may not be satisfied.
Data whose SLO may not be satisfied is one of the following:
The SLO checking/data migration determination unit 231, included in the ILM execution unit 23, references the data management information recording unit 21 to find a set of data whose SLO may not be satisfied (that is, a set of data whose flag FL1 is set). In the subsequent processing, this set of data is treated as checking target data for which the check is made if the SLO is satisfied.
The SLO checking/data migration determination unit 231 references the storage management information recording unit 22. If there is a storage area whose SLA is changed (that is, a storage area whose flag FL3 is set), the SLO checking/data migration determination unit 231 references the data management information recording unit 21 and adds the data, stored in the storage area whose SLA is changed, to the set of checking target data for which the check is made in the subsequent processing to see if the SLO is satisfied.
If there is no SLO checking target data, there is no data
At this time, if the flag FL3 in the storage management information recording unit 22 is set to indicate that the SLA of a storage area is changed after the ILM device 2 performed the ILM processing last, the flag is cleared.
On the other hand, if there is data whose SLO may not be satisfied and, in the current ILM processing, the check is not yet made for some data whether the SLO is satisfied, that is, if there is some data for which the check is to be made for the SLO (Yes in step S11 in
The SLO checking/data migration determination unit 231, included in the ILM execution unit 23, remigrates data, whose SLO was already checked in the current ILM processing, from the set of data selected as described above for SLO checking and, from the remaining data, extracts data for which the check is to be actually made. That is, the SLO checking/data migration determination unit 231 references the information FL21, stored in the data management information recording unit 21 to indicate when data included in the set was processed in step S1, and selects data only from data, which is not yet processed in the current ILM processing, for processing in the subsequent ILM processing.
In the subsequent processing steps, the SLO checking/data migration determination unit 231 checks the data selected in this step (step S12 in
The SLO checking/data migration determination unit 231 reads the SLO and the size of the data, selected in step S12 in
The SLO checking/data migration determination unit 231 also reads the SLA of the storage area, in which the selected data is stored, from the storage management information recording unit 22.
Based on the information that has been read, the SLO checking/data migration determination unit 231 checks if the SLO of the data is satisfied, that is, if the SLO is within the value of the SLA.
If the checking result indicates that the SLO of the data is satisfied, there is no need to move the data from the storage area in which the data is currently stored. Therefore, the SLO checking/data migration determination unit 231 skips steps S14 to S17 (see
If the SLO of the checked data is not satisfied (No in step S13 in
Step S13 in
In step S14 in
The SLO checking/data migration determination unit 231 compares the SLO of the checking target data, selected in step S12 in
If the migration destination of the checking target data is determined in step S14 in
On the other hand, if a migration destination storage area satisfying the SLO is not determined in step S14 in
The SLO checking/data migration determination unit 231 issues an instruction to the data migration execution unit 3 and instructs it to move the checking target data, selected in step S12 in
At the same time, the SLO checking/data migration determination unit 231 calculates the free area sizes of the migration source and destination storage areas after the migration from the size of the checking target data and stores the calculated sizes in the storage management information recording unit 22 (step S16 in
The operation performed by steps S14, S15, and S16 in
The possibility that the SLO is not satisfied is gone because the checking target data was migrated to another storage area so that the SLO is satisfied. So, the SLO checking/data migration determination unit 231 clears the flag FL1 in the data management information recording unit 21 stored therein for the migrated data (step S17).
The SLO checking/data migration determination unit 231 reflects in the information FL21, stored in the data management information recording unit 21, that the SLO of the data processed in step S1 was checked to see if it is satisfied in step S1 in the current processing so that the FL21 indicates that the SLO of the data was already checked in the current ILM processing.
The processing for the checking target data selected in step S12 is terminated and control is passed back to step S11 to check another piece of data to see if the SLO is satisfied and, if necessary, the data is migrated to another storage area where the SLO is satisfied (step S18).
The ILM execution unit 23 included in the ILM device 2 checks if the free area size in one particular storage area is insufficient. To do so, the free area size adjustment/data migration determination unit 232 included in the ILM execution unit 23 acquires the threshold value for determining if the free area of the particular storage area is insufficient and the current free area size from the storage management information recording unit 22.
The free area size adjustment/data migration determination unit 232 compares the current free area size with the free area size threshold and, if the former is larger than the latter, that is, if the free area size of the particular storage area is not insufficient (No in step S21), there is no need for reserving a free area. In this case, step S2 of the ILM processing for the particular storage area is terminated.
Conversely, if the free area size is insufficient and if there is data which is stored in the particular storage area and for which the check is not yet made as to whether the SLO will be satisfied after the data is migrated to another storage area during the current ILM processing (Yes in step S21), the free area size adjustment/data migration determination unit 232 performs the following processing in step S22 to solve the problem of the insufficient free area size in the particular storage area. That is, to reserve a free area in the particular storage area, the free area size adjustment/data migration determination unit 232 selects data from among data, which is stored in the particular storage area and for which the check is not yet made as to whether the data can be migrated to another storage area, data whose SLO will be satisfied even after the data is migrated to that another storage area.
More specifically, the free area size adjustment/data migration determination unit 232 included in the ILM execution unit 23 references the information FL22 stored in the data management information recording unit 21 for each piece of data stored in the particular storage area and extracts a set of data that is not yet checked in step S2 of the current ILM processing as to whether the data can be migrated to another storage area.
From the set, the free area size adjustment/data migration determination unit 232 selects data, which will be actually checked if the SLO will be satisfied after the data is migrated to other storage areas, as a data candidate that will be migrated to another storage area in the following processing steps.
In the following steps, the processing is performed for the data selected in the processing step described above. The above processing is performed in step S22.
The free area size adjustment/data migration determination unit 232 acquires the SLO and size of data, selected in step S22, from the data management information recording unit 21, and acquires the free area size of each storage area included in the storage 5, the threshold used to determine that the free area size of each storage area is insufficient, and the SLA of each storage area from the storage management information recording unit 22.
Using the acquired information, the free area size adjustment/data migration determination unit 232 searches for other storage areas to which the data selected in step S22 can be migrated.
Whether or not a storage area is an area to which the checking target data can be migrated is determined by checking if the SLO of the checking target data is satisfied in the migration destination storage area and if the free area size of the migration destination storage area will not become insufficient when the data is migrated to that storage area.
If two or more storage areas to which checking target data can be migrated are found (Yes in step S24), the free area size adjustment/data migration determination unit 232 determines one of the storage areas as the migration destination (steps S25 and S26).
Conversely, if a storage area to which the checking target data can be migrated is not found (No in step S24), there is no storage area to which the data is migrated and the data is not migrated. That is, if the data cannot be migrated, that is, if no migration destination storage area is found in step S23, the free area size adjustment/data migration determination unit 232 does not execute processing steps S25 and S26, in which the checking target data is migrated, but executes the processing in step S27 that will be described later.
If the checking target data can be migrated from the particular storage area, that is, if the migration destination storage area is determined in step S23, the free area size adjustment/data migration determination unit 232 actually migrates checking target data in step S25 according to the following processing steps.
The free area size adjustment/data migration determination unit 232 sends an instruction, which migrates the data selected in step S22 to the migration destination storage area determined in step S23, to the data migration execution unit 3 to move the data.
At the same time, the free area size adjustment/data migration determination unit 232 calculates the free area sizes of the migration source storage area and the migration destination storage area from the size of the migrated data after the completion of the data migration and stores the calculated result in the storage management information recording unit 22. The processing described above is performed in step S25.
The data selected in step S22 is migrated to another storage area where the SLO is satisfied, without the problem of an insufficient storage area size. Thus, this method invariably satisfies the SLO.
If the flag FL1 stored in the data management information recording unit 21 is set to indicate the possibility that the SLO of the migrated data is not satisfied, the free area size adjustment/data migration determination unit 232 clears the flag (step S26).
The free area size adjustment/data migration determination unit 232 reflects in the information FL22, stored in the data management information recording unit 21, that the data selected for processing in step S2 was checked in step S2 of the current ILM processing as to whether the data can be migrated to another storage area. The information FL22 now indicates that the data was already checked in the current processing.
The processing for the checking target data selected in step S22 is terminated, and control is passed back to step S21 to move data, which can be migrated to another storage area, to solve the problem of an insufficient free area size (step S27).
Next, a second example of the present invention will be described.
The processing time monitor unit 247 in this example starts and stops the operation, and accepts a setting change, responsive to an instruction from an ILM device management I/F 245.
The processing time monitor unit 247 acquires the operation times of an SLO checking/data migration determination unit 231 and a free area size adjustment/data migration determination unit 232, included in an ILM execution unit 23, from an ILM execution control unit 246 and monitors the acquired times.
When the operation times reach the operation time that was set via the ILM device management I/F 245 in advance, the processing time monitor unit 247 sends an instruction to the ILM execution control unit 246 to stop the operation of the ILM execution unit 23.
In response to the stop instruction from the processing time monitor unit 247, the ILM execution control unit 246 suspends the operation of the SLO checking/data migration determination unit 231 and the free area size adjustment/data migration determination unit 232 of the ILM execution unit 23.
The operation of the second example of the present invention is similar to the operation of the first example except that the function of the processing time monitor unit 247 described above is always in operation.
The present invention allows a system, composed of multiple storage areas, to automatically lay out stored data across the storage areas in such a way that the management requirements of the data are satisfied.
For example, when information must be managed under some regulatory control, the configuration according to the present invention allows the requirements to be reflected directly in the management requirements. This means that the management requirements from outside the system can be directly and automatically reflected in the storage management policy.
As a result, the system according to the present invention reduces the workload of a manager and increases the utilization of storage, thus resulting in a reduction in the storage management cost.
While the present invention has been described with reference to the examples above, it is to be understood that the present invention is not limited to the configuration of the examples above and that modifications and changes that may be made by those skilled in the art within the scope of the present invention are included.
It should be noted that other objects, features and aspects of the present invention will become apparent in the entire disclosure and that modifications may be done without departing the gist and scope of the present invention as disclosed herein and claimed as appended herewith.
Also it should be noted that any combination of the disclosed and/or claimed elements, matters and/or items may fall under the modifications aforementioned.
Number | Date | Country | Kind |
---|---|---|---|
2006-199680 | Jul 2006 | JP | national |