With this product, Automated Storage Tiering is implemented based on a Tiering policy.
When a Tiering policy is configured to the following, in relation to the Tier pools using its Tiering policy, the system automatically decides the standards for relocation of data within the volume, and optimally perform the relocation.
Execution Mode: Auto
Data Range of Layer: Automatic Configuration
Automated Storage Tiering relocates so that free space to write new I/O data in is secured in each sub-pool during or after relocation. Evaluation/relocation behaviors vary with the Tier pool usage.
Storage Device | Behavior of Evaluation/Relocation |
|---|---|
ETERNUS DX S4 series (excluding DX60 S4) |
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ETERNUS DX S2 series (excluding DX60 S2) |
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For the ETERNUS DX S4 series (excluding DX60 S4), DX S3 series (excluding DX60 S3), and the ETERNUS AF All-Flash Arrays, the behavior outline of evaluation/relocation is as follows.
Figure 3.9 Behavior Example of Evaluation/Relocation When Tier Pool Usage Rate Is 90 % or Less
Figure 3.10 Behavior Example of Evaluation/Relocation When Tier Pool Usage Rate Is 95 %
Point
If free space of the reserved area size required for evaluation/relocation does not exist in Tier pools, evaluation/relocation fail. In that case, after expanding Tier pool capacity or referring to "2.2 Configuration of Tier Pool" to secure the reserved area required for evaluation/relocation, execute evaluation/relocation.
The following explains the flow of tasks when setting the Execution Mode to "Semi-Auto" or "Manual" and conducting a test run of evaluation and relocation in order to assess the optimal value for the data range of each sub-pool.
Procedures of Tasks When Execution Mode Is "Semi-Auto"
The overview of the procedures of tasks from the test run to the start of operation is as follows:
Start Automated Storage Tiering in relation to the Tier pool that is subject to the test run.
Refer to "Start/Stop Automated Storage Tiering for Tier Pool" in the ETERNUS SF Web Console Guide for information on procedures of operation.
Once Automated Storage Tiering in relation to the Tier pool has been started, collection / evaluation of performance data necessary for relocation of data within the volume is performed.
Confirm the evaluation results.
The evaluation results can be confirmed by following the procedures listed under "Display Relocation Target Volume" in the ETERNUS SF Web Console Guide.
Item | Contents |
|---|---|
Evaluation Date | This is the time and date when the performance data was evaluated. |
Tier Pool Name | This is the name of the Tier pool in which the volume is present. |
FTV Number | This is the volume number. |
FTV Name | This is the volume name of the FTV. |
Policy Name | This is the Tiering policy specified to the Tier pool. |
Execution Mode | This is the Execution Mode of the Automated Storage Tiering. |
Keep High | This is the proportion (%) of data of High that is not to be moved. |
Up to High | This is the proportion (%) of data to be moved from Low / Middle to High. |
Up to Middle | This is the proportion (%) of data to be moved from Low to Middle. |
Keep Middle | This is the proportion (%) of data of Middle that is not to be moved. |
Down to Middle | This is the proportion (%) of data to be moved from High to Middle. |
Down to Low | This is the proportion (%) of data to be moved from High / Middle to Low. |
Keep Low | This is the proportion (%) of data of Low that is not to be moved. |
Status | This is the execution status of relocation.
Volumes in which relocation has been completed are not displayed. Completed results can be confirmed from the relocation history. |
Progress Rate | This is the progress rate of the volumes that are executing relocation. |
Perform the following tasks according to the evaluation results.
Execute the relocation of data within the volume.
Refer to "Start/Stop Relocation" in ETERNUS SF Web Console Guide for information on how to perform the execution.
Continue the collection and the evaluation of the performance data after changing the Tiering policy related to the Tier pool to be tried. Refer to "Change Tiering Policy" in the ETERNUS SF Web Console Guide for information on how to change a Tiering policy.
Procedures of Tasks When Execution Mode Is "Manual"
The overview of the procedures of tasks from the test run to the start of operation is as follows:
Note
When the Execution Mode is "Manual", if the evaluation is started within one hour after performing the following tasks, there may be cases when correct evaluation information cannot be obtained.
Relocation of Data within Volume
Creation of Tier Pool
Addition of FTV
Deletion of FTV
Start Automated Storage Tiering in relation to the Tier pool that is subject to the test run.
Refer to "Start/Stop Automated Storage Tiering for Tier Pool" in the ETERNUS SF Web Console Guide for information on procedures of operation.
Once Automated Storage Tiering in relation to the Tier pool has been started, collection of performance data necessary for relocation of data within the volume is performed.
Evaluate the collected performance data.
Refer to "Evaluate Access Status Data for Tier Pool" in the ETERNUS SF Web Console Guide for information on how to perform the evaluation.
Confirm the evaluation results.
The evaluation results can be confirmed by following the procedures listed under "Display Relocation Target Volume" in the ETERNUS SF Web Console Guide. Refer to the table of step 2 of "Procedures of Tasks When Execution Mode Is "Semi-Auto"" for an explanation of the displayed information.
Perform the following tasks according to the evaluation results.
Execute the relocation of data within the volume.
Refer to "Start/Stop Relocation" in the ETERNUS SF Web Console Guide for information on how to perform the execution.
Continue the collection and the evaluation of the performance data after changing the Tiering policy related to the Tier pool to be tried. Refer to "Change Tiering Policy" in the ETERNUS SF Web Console Guide for information on how to change a Tiering policy.
Point
Once it has been confirmed that there are no problems in the test run of evaluation and relocation, it is recommended that Automated Storage Tiering is operated upon changing the Execution Mode of the Tiering policy to "Auto".
Note
There is an upper limit for the total number of Tier pools used that can simultaneously evaluate the Automated Storage Tiering access status data. The value 2 PB is set by default, but can be customized. Refer to "Customizing Automated Storage Tiering Configuration File" in the ETERNUS SF Installation and Setup Guide for information on how to customize the value.
Automated Storage Tiering might relocate to the same disk type of the same layer when defining it on the following conditions.
Each layer of the Tier pool is made by the same disk type.
When FTV is made, Priority FTSP is specified with "Auto" or sub-pool that is the same disk type.
The value is displayed in Keep Low, Keep Middle, and Keep High, and when the relocation result is displayed because the movement of the layer is not generated in the relocation of the same layer to the same disk type, and "0" might be displayed in Up to High, Up to Middle, Down to Middle, and Down to Low.
If approximately 10% in the Tier pool capacity does not exist as the reserved area, evaluation/relocation does not complete normally. For relocation, each sub-pool must set aside about 10% (fixed) for use as a reserved area.
