StorPool only serves block devices to the supported OS platforms.
StorPool aggrates direct-attached storage from multiple x86 servers into one or more pools. There can be multiple pools in each StorPool cluster, eg. an SSD pool and a HDD-only pool.
Volumes are striped widely across many drives in the pool. Copies (replicas) are guaranteed to be on different servers or different chassis; this ensures high availablity of data access. Thus StorPool aggregates the capacity and performance of all drives in each pool.
StorPool uses a shared-nothing architecture where all servers participate on an equal basis - there are no meta data servers or active-standby roles, just servers on a flat network.