User guide

Appendix F
Recovering From Hard Drive Failure
The purpose of fault-tolerant configurations on the Compaq RAID Array 4000
Controller is to protect against data loss due to drive failure. Although the
RA4000 Controller firmware is designed to protect against normal drive
failure, it is imperative that you perform the correct actions to recover from a
drive failure without inadvertently inducing any additional drive failures.
Multiple drive failures in the same array generally result in data loss
(exceptions include failures following activation of a spare drive, and failure
of drives in a mirroring configuration that are not mirrored to one another).
Recognizing a Drive Failure
A drive failure can be recognized by the system operator in one of several
ways:
■ Amber LED illuminates on failed drives in a hot-pluggable tray. This,
however, assumes the storage system is powered-on and connected
properly. Note that the amber LED may illuminate briefly when a hot-
pluggable drive is inserted - this is normal.
■ Amber LED illuminates on the front of the Compaq RA4100 Array if
drives failed inside (other problems such as fan failure or over-
temperature conditions also cause this LED to illuminate).
■ A Power-On Self-Test (POST) message lists failed drives whenever the
system is restarted (assumes that the controller detects one or more good
drives).
■ Array Diagnostic Utility (ADU) lists all failed drives. An online version
on ADU is also available in Windows NT environments.