Pool-VOLs are grouped together to create a pool. Every pool must have a pool-VOL with system area.
If you increase the pool capacity by adding a pool-VOL, a portion of the existing data in the pool automatically migrates from an older pool-VOL to the newly added pool-VOL, balancing the usage levels of all the pool-VOLs. If you do not want to automate balancing of the usage levels of pool-VOLs, contact customer support for assistance.
Page usage balancing for each parity group is automatically performed under the following conditions:
- Pool capacity expansion
- Zero data page reclamation
- A zero data page is reclaimed by a page release instruction from the host, such as the Write Same command.
Dynamic Provisioning does not automatically balance the usage levels among pool-VOLs if the cache memory is not redundant or if the pool usage reaches up to the threshold.
The pool-VOLs contained in a pool can be added or deleted. Removing a pool-VOL does not delete the pool or any related V-VOLs. You must delete all V-VOLs related to the pool before the pool can be deleted. When the pool is deleted, all data in the pool is also deleted.