FTVs only can be created in a Tier Pool.
Configuration of FTV is performed with the Web Console. This cannot be performed with the ETERNUS Web GUI.
When the total capacity of the FTV (Thick) is specified for the allocation of the physical area with the Allocation setting during volume creation, the physical area (FTRPE) of the total capacity is allocated. For that reason, regardless of whether data is written, evaluation/relocation of the access status data is always performed for the total capacity of the FTRPE in FTVs where the Allocation is "Thick".
The FTV usage rate is the proportion of each layer when the total physical capacity assigned to the FTV is expressed as 100. As values are displayed upon rounding of the second decimal place, there may be cases when the total does not add up to 100%.
Setting FTV Capacity Quota Share
You can set the quota share for the capacity of each sub-pool in the Tier pool when creating or making changes to FTV.
For FTV with a set quota share, relocation to each sub-pool is carried out according to the quota share.
For FTV for which a quota share has not been specified, relocation is carried out according to the Tiering policy specified in the Tier pool.
Example
If the FTVs do not need high-speed response in the business though accessed frequently, set 100% to Low Quota Share of the FTVs.
The relocation logic for the case when the FTV quota share has been specified is as follows:
For FTRPE that constitutes FTV, IOPS values are sorted in ascending order and relocation to the sub-pool performed so that the specified capacity quota share starts with the FTRP with high IOPS values.
If free space that corresponds to the quota share cannot be secured, relocation is performed with as much capacity as can be secured. Therefore, relocation may not proceed according to the specified quota share.
Figure 3.4 Relocation When Capacity Quota Share Is Specified for Each Layer
Figure 3.5 Relocation When Free Space Corresponding to Specification of Capacity Quota Share Cannot Be Secured
Figure 3.6 Relocation When Capacity Quota Share Is Specified for Specific Layer
Note
Implement the changing / deletion / formatting of an FTV after updating the administration information of the FTV.
If FTV configuration has been changed on the ETERNUS Disk storage system side, perform for the target ETERNUS Disk storage system the operations described in "Reload ETERNUS Disk Storage System Configuration Information" in the ETERNUS SF Web Console Guide in order to make the management information of FTV up-to-date.
Physical allocation to the FTV is on a per block basis.
The capacity displayed for usage share (capacity) of the FTV is calculated from the number of blocks allocated by each layer. For this reason, the total usage capacity of each layer may not correspond to the used capacity of the FTV.
Storage Device | Capacity Per Block (*1) |
|---|---|
ETERNUS DX S4 series (excluding DX60 S4) | 21 MB, 42 MB, 84 MB, or 168 MB |
ETERNUS DX S2 series (excluding DX60 S2) | 1,344 MB |
*1: For the ETERNUS DX S4 series (excluding DX60 S4), DX S3 series (excluding DX60 S3), and the ETERNUS AF series, the capacity per block is displayed as "Chunk Size" on the Web Console.
