HP XP7 Storage - Manual (Page 275)

CAUTION: When you create the Thin Provisioning or Thin Provisioning Z pool, if you specify
Mixable for RAID level to display the Select Pool VOLs window, external volumes with the cache
mode set to disabled are not displayed in the Available Pool Volumes table because they cannot
coexist with volumes of the other RAID levels:
When you select these volumes in the Select Pool VOLs window, specify a hyphen (-) for RAID level.
Add
When you click Add, the configured information is added to the right side of the Selected Pools
table.
Create Pools wizard 275