The following are the notes on use for the RAID group deletion function:
If the deletion of the RAID group in the Tier pool that is being formatted is executed, the RAID group deletion process does not finish until the Tier pool is completely formatted. Use ETERNUS Web GUI to check whether the Tier pool is being formatted.
When a RAID group is being deleted, there are some operations that cannot be executed for Tier pools that contain the RAID group. In addition, even upon completion of the RAID group deletion, if the information for a Tier pool containing the deleted RAID group has not been reconfigured, there are some operations that cannot be executed for the Tier pool and the FTVs that belong to the Tier pool.
The operations that cannot be executed are as follows:
Changing the Tier pool
Deleting the Tier pool
Changing the number of tiers of the Tier pool
Expanding the capacity of a sub-pool
Starting Automated Storage Tiering
Starting and Stopping the Tier pool balancing
Deleting the RAID group
Creating the FTV in which the quota share is set
Changing the FTV in which the quota share is set
If the operation cannot be performed, re-execute the operation either after waiting for a while or after reconfiguring the Tier pool information by performing the Status Update operation for Automated Storage Tiering. Refer to "Update Automated Storage Tiering Information" in the ETERNUS SF Web Console Guide for information on how to perform the Status Update operation.
If the conditions for deletion of RAID groups are not satisfied while a RAID group is deleted, the RAID group deletion process is suspended. If the process is suspended, the error is notified to the Management Server by the SNMP trap from the ETERNUS Disk storage system and Shrinking for the Tier pool is displayed as "Error".
In this case, after stopping the suspended RAID group deletion process, remove the error cause so that the conditions for deletion of RAID groups are satisfied. Refer to "Stop RAID Group Deletion in Tier Pool" in the ETERNUS SF Web Console Guide for information on how to stop the RAID group deletion process.
Deleting RAID groups may cause data bias in the sub-pool and a difference in the access performance. To eliminate data bias, perform a Tier pool balancing. Refer to "Start/Stop Tier Pool Balancing" in the ETERNUS SF Web Console Guide for information on how to perform a Tier pool balancing.
In addition, a Tier pool balancing can be performed after RAID groups are deleted and while RAID groups are being deleted.
If a sub-pool is deleted by deleting RAID groups, the FTV quota share that has been set for the sub-pool is cleared.
If a RAID group deletion is completed when you stop the RAID group deletion process, the RAID group deletion process terminates normally but the RAID groups remain deleted.
If FTV is set as the synchronization target volume using the Storage Cluster function, delete RAID groups from both boxes so that the Tier pool configuration is the same on both the Primary Storage and the Secondary Storage. Refer to "Storage Cluster Function" in the ETERNUS SF Storage Cruiser Operation Guide for details of the Storage Cluster function.
