PowerFlex Storage Pools are elastic containers for physical drive capacity.

Add additional disks to the existing pool (Option A): You can expand a Storage Pool by physically inserting new drives into existing nodes and adding them to the pool, or by adding completely new nodes (populated with drives) to the cluster.

The Process: When new devices are added to a Storage Pool, the PowerFlex MDM automatically initiates a Rebalance operation. It moves existing data chunks from the full drives to the new empty drives until the usage percentage is equalized across all drives in the pool. This process is transparent to the host and increases both the capacity and the I/O performance of the pool.