Monitoring Status Through Software; Checking The Leds - IBM TotalStorage DS4000 Hardware Maintenance Manual

Monitoring status through software

Use the storage management software to monitor the status of the storage server.
Run the software constantly, and check it frequently.
The storage management software provides the best way to diagnose and repair
storage server failures. The software can help you:
v Determine the nature of the failure
v Locate the failed component
v Determine the recovery procedures to repair the failure
Although the storage server has fault LEDs, these lights do not necessarily indicate
which component failed or needs to be replaced, or which type of recovery
procedure that you must perform. In some cases (such as loss of redundancy in
various components), the fault LED does not turn on. Only the storage
management software can detect the failure.
For example, the recovery procedure for a Predictive Failure Analysis
(impending drive failure) on a drive varies depending on the drive status (hot
spare, unassigned, RAID level, current logical drive status, and so on). Depending
on the circumstances, a PFA flag on a drive can indicate a high risk of data loss (if
the drive is in a RAID 0 volume) or a minimal risk (if the drive is unassigned).
Only the storage management software can identify the risk level and provide the
necessary recovery procedures.
Note: For PFA flags, the General-system-error LED and Drive fault LEDs do not
Recovering from a storage server failure might require you to perform procedures
other than replacing the component (such as backing up the logical drive or failing
a drive before removing it). The storage management software gives these
procedures.
Attention: Not following the software-recovery procedures can result in data loss.

Checking the LEDs

The LEDs display the status of the storage server and components. Green LEDs
indicate a normal operating status; amber LEDs indicate a possible failure.
It is important to check all the LEDs on the front and back of the storage server
when you turn on the power. In addition to checking for faults, you can use the
LEDs on the front of the storage server to determine whether the drives are
responding to I/O transmissions from the host.
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IBM TotalStorage DS4000: Hardware Maintenance Manual
turn on, so checking the LEDs will not notify you of the failure, even if the
risk of data loss is high.
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(PFA) flag