User's Manual

Hard Drive Installation and Replacement
HP Smart Array 641/642 Controller User Guide E-7
HP CONFIDENTIAL
Writer: John Turner File Name: m-appe hard drive installation & replacement
Codename: darkmatter - antimatter Part Number: 309311-001 Last Saved On: 11/7/02 5:07 PM
CAUTION: Sometimes, a drive that has previously been failed by the controller 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.
There are several other factors to remember when replacing a hard drive:
• Non-hot-pluggable drives should be replaced only while the system is powered
down.
• Hot-pluggable drives can be removed and replaced at any time, whether the host
or storage system power is on or off.
When a hot-pluggable drive is inserted, all disk activity on the array pauses while
the new drive is spinning up (usually 20 seconds or so). If the drive is inserted
while power is on, in a fault-tolerant configuration, data recovery to the
replacement drive begins automatically (indicated by the blinking Online LED).
• Replacement drives must have a capacity no less than that of the smallest drive in
the array. The controller immediately fails drives that have insufficient capacity,
before automatic data recovery can begin.
• When you set the SCSI ID jumpers manually, check the ID value to be sure that
the correct physical drive is being replaced. Set the same ID value on the
replacement drive to prevent SCSI ID conflicts.
CAUTION: In systems using external data storage, take care that the server is the
first unit to be powered down and the last to be powered back up. Doing this ensures
that the system does not erroneously mark the drives as failed when the server is
next powered up.
The rebuild operation takes several hours, even if the system is not busy while the
rebuild is in progress. System performance and fault tolerance are both affected until
the rebuild has finished. Therefore, replace drives during low activity periods
whenever possible. In addition, be sure that all logical volumes on the same array as
the drive being replaced have a current, valid backup.