Start Balancing Flexible Tier Pool

Overview

This function starts Flexible Tier Pool (FTRP) balancing sessions.

The FTRP balancing function equalizes unevenly allocated physical area in the Flexible Tier Sub Pools (FTSPs) that configure an FTRP. By using this function, the physical allocated areas are reallocated equally among the RAID groups in the FTSPs. The I/O access to the FTV is distributed almost equally to the RAID groups in the FTSP.

Requirements for an FTRP to be Balanced

  • The status is "Available", "Partially Readying", or "Exposed"

  • Balancing of the selected FTRP is not being performed

  • Free space, which can be used for balancing, exists in the FTSPs in the target FTRP

Caution

  • Before balancing the FTRP, make sure that "Used Capacity" for all the FTSPs in the target FTRP is less than 50% of "Total Capacity". If this requirement is not satisfied and the capacity runs out, the FTRP balancing may not be complete.

    "Used Capacity" and "Total Capacity" for FTSP can be checked from the [Flexible Tier Pool Detail] screen ("Flexible Tier Sub Pool" tab). Refer to the [Flexible Tier Pool (Basic Information)] function for details.

  • Even after the FTRP balancing session is performed, the physical allocation between the FTVs and the FTSPs does not change.

  • The FTRP balancing function extracts up to 32 balanceable FTVs (*1) that have a low balancing level from the selected FTRP and performs balancing sessions in the FTSPs. Note that FTVs are not extracted as balancing targets in certain conditions. For example, FTVs with a high balancing level, FTVs that are undergoing RAID migration, or FTVs that are undergoing capacity optimization.

    *1  :  Up to 32 sessions, which include FTV balancing sessions, TPV balancing sessions, and RAID migration sessions, can be performed at the same time. An FTRP balancing session is performed in each FTRP. Note that the number of FTV balancing sessions that are performed at the same time cannot be specified.
  • Balancing of FTVs in the following conditions is not available:

    • FTVs which capacity is 20 GB or less

    • FTVs which used capacity is 10 GB or less

    The FTV capacity can be checked in the [Flexible Tier Pool Detail (Volume)] screen. Refer to the [Flexible Tier Pool (Basic Information)] function for details.
  • FTRP balancing cannot be started in the following conditions:

    • The Thin Provisioning function is disabled

    • The Automated Storage Tiering feature is disabled.

    • The maximum number of volumes are already registered in the storage system

    • The total number of TPV balancing sessions, RAID migration sessions, and Non-disruptive Storage Migration sessions that are running in the storage system is 32

    • The total capacity of TPV balancing sessions, RAID migration sessions, and Non-disruptive Storage Migration sessions that are running in the storage system is 128 TB

    • The RAID group diagnosis is being performed in the storage system

    • The disk diagnosis is being performed in the storage system

    • The capacity optimization is being performed for all of the balancing target FTVs in the FTRP

    • ODX is being performed for all of the balancing target FTVs in the FTRP

  • When FTRP balancing is performed, the used FTRP capacity may temporarily exceed the threshold. If the used capacity exceeds the threshold, "Attention" or "Warning" is displayed in the "Used Status" field for the FTRP. The usage of the FTRPs is displayed in the [Flexible Tier Pool] screen. Refer to the [Flexible Tier Pool (Basic Information)] function for details.

Note

  • FTRP balancing can be performed during the work I/O.

  • The balancing levels of FTRPs and FTSPs, and the progress of the FTRP balancing sessions can be checked. Refer to the [Flexible Tier Pool (Basic Information)] function for details.

  • The progress of a balancing FTV can be checked in the [Volume Detail] screen. Refer to the [Volume (Basic Information)] function for details.

User Privileges

Availability of Executions in the Default Role

Default role Availability of executions
Monitor  
Admin
StorageAdmin
AccountAdmin  
SecurityAdmin  
Maintainer

Refer to "User Roles and Policies" for details on the policies and roles.

Operating Procedures

  1. Select the FTRP for which balancing is to be started and click [Start Balancing FTRP] in [Action].

    → A confirmation screen appears.

  2. Click the [OK] button.

    → FTRP balancing starts.

  3. Click the [Done] button to return to the [Flexible Tier Pool] screen.