You can extend the availability of your hardware by providing
battery backup to your nodes and disks. HP's PowerTrust Uninterruptible
Power Source (UPS) can provide this protection from momentary power
loss.
Disks should be attached to power circuits in such a way that
mirror copies (non-OPS data only) are attached to different power
sources. The boot disk should be powered from the same circuit as
its corresponding node.
The cluster lock disk (used as a tie-breaker when re-forming
a cluster) should have its own power supply, separate from the power
supply used by the nodes in the cluster. Your HP representative
can provide more details about the layout of power supplies, disks,
and LAN hardware for clusters.