HP 273914-B21 - Smart Array 6404/256 RAID Controller User Manual page 44

44 HP Smart Array 6400 Series Controllers User Guide
If you set the SCSI ID jumpers manually:
Before replacing a degraded drive:
Open Systems Insight Manager and inspect the Error Counter window for
each physical drive in the same array to confirm that no other drives have
any errors. (For details, refer to the Systems Insight Manager documentation
on the Management CD.)
Be sure that the array has a current, valid backup.
Use replacement drives that have a capacity at least as great as that of the
smallest drive in the array. The controller immediately fails drives that have
insufficient capacity.
To minimize the likelihood of fatal system errors, take these precautions when
removing failed drives:
Do not remove a degraded drive if any other drive in the array is offline (the
Online LED is off). In this situation, no other drive in the array can be
removed without data loss.
Exceptions:
Do not remove a second drive from an array until the first failed or missing
drive has been replaced and the rebuild process is complete. (The rebuild is
complete when the Online LED on the front of the drive stops blinking.)
These cases are the exceptions:
Check the ID value of the removed drive to be sure that it corresponds to
the ID of the drive marked as failed.
Set the same ID value on the replacement drive to prevent SCSI ID
conflicts.
When RAID 1+0 is used, drives are mirrored in pairs. Several drives can
be in a failed condition simultaneously (and they can all be replaced
simultaneously) without data loss, as long as no two failed drives belong
to the same mirrored pair.
When RAID ADG is used, two drives can fail simultaneously (and be
replaced simultaneously) without data loss.
If the offline drive is a spare, the degraded drive can be replaced.