You can select which disk units you want to exclude from the parity set as long as they do not contain parity data.
For RAID 5 protection, you can exclude a protection disk unit with a model number of 070, or 080 if it is compressed, because these disk units do not store parity data.
For RAID 6 protection, you can exclude a protected disk unit with a model number of 090 because it is a disk unit that does not store parity data.
When you exclude a disk unit from the parity set, the data on this 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.
If you want to exclude disk units from an independent disk pool that is unavailable, you can do so when your system is fully restarted. For all other disk pools, you need to restart your system to dedicated service tools (DST) mode before excluding them from a parity set.
To exclude a disk unit from a parity set, follow these steps: