You can create a storage pool using available SDs. The storage pool can be expanded up to 256 SDs.
To achieve the best performance when creating a tiered storage pool, store the metadata tier (Tier 0) on the storage system with the highest performance.If all system drives have the same performance characteristics, then create an untiered storage pool.
Before creating a storage pool, make sure system drives are enabled and ready to use.
The following video will walk you through creating a storage pool.