Recognizing drive failure, Effects of a drive failure, Compromised fault tolerance – HP D2220sb-Storage-Blade User Manual
Page 33
Troubleshooting 33
Answer
Possible reasons
Possible solutions
LED ("
" on page
) indicates
normal temperature.
The drive drawer was open too long and
triggered critical overtemperature alerts.
Restart the partner server blade.
Recognizing drive failure
A steadily illuminated Fault LED on a drive indicates that the drive has failed.
Other indications of failed drives include the following:
•
ACU represents failed drives with a distinctive icon.
•
HP SIM can detect failed drives remotely across a network. (For more information about HP SIM, refer
to the documentation on the Management CD.)
•
ADU lists all failed drives.
For more information about diagnosing drive problems, see the HP ProLiant Gen8 Troubleshooting Guide,
Volume 1.
CAUTION:
Sometimes, a drive that has previously failed may seem to be operational after the
system is power-cycled or (for a hot-pluggable drive) after the drive has been removed and
reinserted. However, continued use of such marginal drives may eventually result in data loss.
Replace the marginal drive as soon as possible.
Effects of a drive failure
When a drive fails, all logical drives that are in the same array are affected. Each logical drive in an array
may be using a different fault-tolerance method, so each logical drive can be affected differently.
•
RAID 0 configurations cannot tolerate drive failure. If any physical drive in the array fails, all
non-fault-tolerant (RAID 0) logical drives in the same array will also fail.
•
RAID 1+0 configurations can tolerate multiple drive failures as long as no failed drives are mirrored to
one another.
•
RAID 5 configurations can tolerate one drive failure.
•
RAID 50 configurations can tolerate one failed drive in each parity group.
•
RAID 6 configurations can tolerate simultaneous failure of two drives.
•
RAID 60 configurations can tolerate two failed drives in each parity group.
•
RAID 1 (ADM) configurations can tolerate multiple drive failures if no more than two drives, mirrored to
one another, fail.
Compromised fault tolerance
CAUTION:
When fault tolerance is compromised, data loss can occur. However, it may be
possible to recover the data. For more information, see "Recovering from compromised fault
tolerance."