The Flash Pool technology has some configuration requirements that you should be aware of before planning to use it in your storage architecture.
Flash Pool aggregates cannot be used in the following configurations:
You cannot use the following types of storage objects in Flash Pool aggregates:
Partitioned HDDs can be used for the HDD RAID groups of a Flash Pool aggregate.
You can use Flash Pool aggregates and the Flash Cache module (WAFL external cache) in the same system. However, data stored in a Flash Pool aggregate is not cached in the Flash Cache module. Flash Cache is reserved for data stored in aggregates composed of only HDDs.
You can use data compression on volumes associated with a Flash Pool aggregate. However, compressed blocks are cached in the Flash Pool cache only for read operations; compressed blocks are not cached for write operations.
Data in read-only volumes, such as SnapMirror or SnapVault destinations, is cached in the Flash Pool cache.
Flash Pool aggregates can be created from mirrored aggregates; however, the SSD configuration must be kept the same for both plexes.
If you create a Flash Pool aggregate using an aggregate that was created using Data ONTAP 7.1 or earlier, the volumes associated with that Flash Pool aggregate do not support write caching.