Pool-VOL requirements

Volume type

Logical volume (LDEV)

You can mix non-pool-VOLs and pool-VOLs in a single parity group. However, for performance reasons, a parity group should contain either only non-pool-VOLs or only pool-VOLs.

DP pool-VOLs cannot be used for any other purpose. For instance, you cannot specify these volumes as:

• Volumes used by ShadowImage, Volume Migration, Thin Image Advanced, TrueCopy, global-active device, or Universal Replicator
• Volumes reserved by Data Retention Utility
• Data Retention Utility volumes with the Protect, Read Only, or S-VOL disable attribute
• LDEVs whose is status other than Normal, Correction Access, or Copying
• Command devices
• Quorum disks used by global-active device

RAID level for a Dynamic Provisioning pool

Pool-VOLs of RAID 6, RAID 5, RAID 1and external volumes can coexist in the same pool. For pool-VOLs in the same pool:

Use RAID 6 as the RAID level for pool-VOLs. If the recovery time for a pool failure due to a drive failure is not acceptable, consider using RAID 6 as the RAID level for the pool-VOLs.

Pool-VOLs of different RAID levels can coexist in the same pool. Set one RAID level for pool-VOLs. The RAID level in the pool should be either of RAID 6 or RAID 5. If you register pool-VOLs with multiple RAID levels to the same pool, the I/O performance depends on the RAID levels of pool-VOLs to be registered. In that case, note the I/O performance of the drives.

Data drive type for a Dynamic Provisioning pool

SSDs and external volumes are available for the drive type. All drive types can coexist in the same pool with the following considerations:

• Pools should be built from pool-VOLs of the same capacity, type, and RAID level. If multiple pool-VOLs with different drive types are registered in the same pool, the I/O performance depends on the drive type of the pool-VOL to which the page is assigned. Therefore, if different drive types are registered in the same pool, ensure that the required I/O performance is not degraded by using less desirable drive types.
• If multiple data drives coexist in the same pool, avoid using data drives that are different capacities.

Volume capacity

Internal volume: From 8 GB to 2.9 TB

External volume: From 8 GB to 4 TB

External volume with the data direct mapping attribute: From 8 GB to 256 TB

LDEV format

The LDEV format operation can be performed on pool-VOLs only when there are no V-VOLs defined for the pool, or all V-VOLs defined for the pool are blocked.

Path definition

You cannot specify a volume with a path definition as a pool-VOL.