Volume type

Logical volume (LDEV)

While pool-VOLs can coexist with other volumes in the same parity group, for best performance:

• pool-VOLs for a pool should not share a parity group with other volumes.

• pool-VOLs should not be located on concatenated parity groups.

Pool-VOLs cannot be used for any other purpose. For instance, you cannot specify the following volumes as Dynamic Provisioning and Dynamic Tiering pool-VOLs:

• Volumes used by ShadowImage, Volume Migration, TrueCopy, or Universal Replicator

• Volumes already registered in Thin Image, Dynamic Provisioning, or Dynamic Tiering pools

• Volumes used as Thin Image P-VOLs or S-VOLs

• Data Retention Utility volumes with a Protect, Read Only, or S-VOL Disable attribute

• Volumes whose LDEV status is other than Normal or Normal (Quick Format)

You cannot specify volumes in blocked status or volumes in copying process.

• Command devices

RAID level for a Dynamic Provisioning pool

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

• RAID 6 is the recommended RAID level for pool-VOLs, especially for a pool where the recovery time of a pool failure due to a drive failure is not acceptable.

• Pool-VOLs of the same drive type with different RAID levels can coexist in the same pool. Note that we recommend that you use the following configuration:

• Set one RAID level for pool-VOLs.

If you register pool-VOLs with multiple RAID levels, 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 disks.

• Pool-VOLs on external volumes cannot have a mix of cache modes set to enable and disable.

• For internal and external pool-VOLs to coexist, the cache mode of the external volume must be set to enable.

• For the RAID configuration that can be applied to pool volume, see RAID level for CV.

RAID level for a Dynamic Tiering pool

RAID 1, RAID 5, or RAID 6 can be applied. Pool-VOLs of RAID 1, RAID 5, RAID 6, and the external volume can coexist in the same pool.

For pool-VOLs in a pool:

• RAID 6 is the recommended RAID level for pool-VOLs, especially for a pool where the recovery time of a pool failure due to a drive failure is not acceptable.

• Pool-VOLs of the same drive type with different RAID levels can coexist in the same pool. Note that we recommend that you use the following configuration:

• Set one RAID level for pool-VOLs.

If you register pool-VOLs with multiple RAID levels, 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 disks.

• Because the speed of RAID 6 is slower than other RAID levels, tiers that use other RAID levels should not be placed under a tier that uses RAID 6.

• Pool-VOLs of an external volume must have cache mode enabled.

• For the RAID configuration that can be applied to pool volume, see RAID level for CV.

Data drive type for a Dynamic Provisioning pool

SSD*, SAS15K, SAS10K, SAS7.2K, and external volume can be used as the data drive type. These data drive types can coexist in the same pool.

Cautions:

• We recommend that drives with different types do not coexist in a same pool. 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 a same pool, we recommend not using data drives that are same types and different capacity sizes.

Data drive type for a Dynamic Tiering pool

SSD*, SAS15K, SAS10K, SAS7.2K, and external volume can be used as the data drive type. These data drive types can coexist in the same pool.

Cautions:

• If multiple data drives coexist in a same pool, we recommend not using data drives that are same types and different capacity sizes.

Volume capacity

Internal volume: From 8 GB to 2.9 TB

External volume: From 8 GB to 4 TB

LDEV format

The LDEV format operation can be performed on pool-VOLs if one of these conditions is satisfied:

• The DP-VOL defined for the pool does not exist.

• All DP-VOLs defined for the pool are blocked.

Path definition

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

* Includes SLC/MLC for SSD, and FMD.