Disk issues

GPFS uses only disk devices prepared as Network Shared Disks (NSDs). However NSDs might exist on top of a number of underlying disk technologies.

NSDs, for example, might be defined on top of Fibre Channel SAN connected disks. This information provides detail on the creation, use, and failure of NSDs and their underlying disk technologies.

These are some of the errors encountered with GPFS disks and NSDs:

NSD and underlying disk subsystem failures
GPFS has declared NSDs built on top of AIX logical volumes as down
Disk accessing commands fail to complete due to problems with some non-IBM disks
Persistent Reserve errors
GPFS is not using the underlying multipath device