HP 5300 - Manual (Page 125)

Hard Drive Installation and Replacement
E-8 HP Smart Array 5300 Controller User Guide
HP CONFIDENTIAL
Writer: Jennifer Hayward File Name: o-appe hard drive installation and replacement
Codename: SilverHammer Part Number: 135606-005 Last Saved On: 10/8/02 11:22 AM
• Failure of a drive that is not mirrored to any other failed drives (in a RAID 1+0
configuration)
• Failure of a second drive in a RAID ADG configuration
Minimizing Fatal System Errors During Rebuild
When a hard drive is replaced, the controller gathers fault-tolerance data from the
remaining drives in the array. This data is then used to rebuild the missing data
(originally on the failed drive) onto the replacement drive. If more than one drive is
removed at a time, the fault-tolerance data is incomplete. The missing data cannot
then be reconstructed and is likely to be permanently lost.
To minimize the likelihood of fatal system errors, take these precautions when
removing failed drives:
• Do not remove a degraded drive if any other member of the array is offline (the
Online LED is off). In this condition, no other drive in the array can be removed
without data loss.
There are some exceptions:
— 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 an online spare has an unlit Online LED (it is offline), the degraded drive
can still be replaced.
• 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. (When the rebuild is
complete, the Online LED on the front of the drive stops blinking.)
There are some exceptions:
— In RAID ADG configurations, any two drives in the array can be replaced
simultaneously.