IBM TotalStorage FAStT200, Installation And User Manual

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Chapter 4. Operating the storage server
29
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
®
(PFA) flag
(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 turn
on, so checking the LEDs will not notify you of the failure, even if the risk of
data loss is high.
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 if the drives are responding to I/O
transmissions from the host.
For information about the LEDs on the front of the storage server, see:
• Figure 6 on page 30
• Table 3 on page 30
For information about the LEDs on the back of the storage server, see:
• Figure 8 on page 32
• Table 4 on page 31
• Table 5 on page 32