Excluding disk units from a parity set

You can select which disk units you want to exclude from the parity set as long as they do not contain parity data.

You can exclude a protected disk unit with a model number of 070 or 090 because these disk units do not store parity data.

When you exclude a disk unit from the parity set, the data on the disk unit remains there but is no longer protected by device parity protection. If the disk pool is protected, you are not allowed to exclude a disk unit that belongs to that disk pool from a parity set. The system does not allow unprotected disk units to reside in a protected disk pool.

You need to restart your partition to dedicated service tools (DST) mode before excluding disk units from a parity set.

Note: Not all disk units in a parity protected set are eligible to be excluded. To be eligible, the parity set must contain at least four devices with RAID 5 protection and at least five devices for RAID 6 protection, and the candidate devices cannot contain parity data.

To exclude a disk unit from a parity set, follow these steps:

On the Dedicated Service Tools (DST) display, select Work with disk units.
On the Work with Disk Units display, select Work with disk configuration.
On the Work with Disk Configuration display, select Work with device parity protection.
On the Work with Device Parity Protection display, select Exclude unit from device parity protection.
On the Exclude Unit from Device Parity Protection display, select the disk unit to exclude.