HP Smart Array Cluster Storage System

Hardware Options Installation
HP Smart Array Cluster Storage System User Guide 3-3
HP CONFIDENTIAL
Writer: Rob Weaver File Name: d-ch3 Hardware Options Installation
Codename: Aurora Part Number: 240333-003 Last Saved On: 11/6/02 1:04 PM
Replacing Hot-Plug SCSI Hard Drives
CAUTION: If you must replace a hot-plug drive, follow the guidelines in this section.
Failure to do so can result in data loss and can void the warranty.
RAID 0 is not a fault-tolerant configuration. Never remove a drive from a RAID 0
array unless it has failed. Drive failure is indicated by an amber drive failure LED. In
a RAID 0 configuration, removal of an operating drive results in data loss. To
remove a drive without losing data, always back up the entire array, replace the drive,
and restore the entire array. Backing up a single drive and replacing it does not
restore the array.
Some instances exist in which you may replace a drive in RAID 1, 5, and ADG
configurations. To determine when drive replacement is possible without data loss,
use the hot-plug SCSI hard drive LEDs combination table in Chapter 1, “Component
Identification.”
Follow these additional guidelines when replacing drives:
• Never remove more than one drive at a time (or two drives if you are using
ADG). When you replace a drive, the controller uses data from the other drives
in the array to reconstruct data on the replacement drive. If you remove more
than one drive, a complete data set is not available to reconstruct data on the
replacement drive(s) and permanent data loss could occur.
• Never remove a drive while the controller is rebuilding another drive. A
drive’s online LED flashes green while it is being rebuilt. The controller requires
the data from all other drives to rebuild the replacement drive.
• If the system has an online spare drive, wait for it to complete rebuilding
before replacing the failed drive. When a drive fails, the online spare becomes
active and begins rebuilding as a replacement drive. After the online spare has
completed Automatic Data Recovery (the online LED is continuously lit),
replace the failed drive with a new replacement drive. Do not replace the failed
drive with the online spare. The system automatically rebuilds the replacement
drive and resets the spare drive to an available state.
• If you replace a drive while the system is off, it may be necessary to rebuild
the replaced drive.