Shared external disk access

The PowerHA® SystemMirror® software supports two methods of shared external disk access: nonconcurrent and concurrent.

Nonconcurrent shared external disk access
In a nonconcurrent environment, only one node has access to a shared external disk at a given time.
Concurrent shared external disk access
The concurrent access feature enhances the benefits provided by a PowerHA SystemMirror cluster. Concurrent access allows simultaneous access to a volume group on a disk subsystem attached to multiple (up to 16) nodes.

Parent topic: PowerHA SystemMirror software components