Hard Drive Installation and Replacement
D-6
Compaq Smart Array 5i Plus Controller and Battery Backed Write Cache User Guide
COMPAQ CONFIDENTIAL
Writer: Amy L. Laffitte File Name: m-appd Hard Drive Installation and Replacement
Codename: Executor Part Number: 266328-001 Last Saved On: 4/18/02 2:51 PM
Automatic Data Recovery
Automatic Data Recovery is an automatic background process that rebuilds data onto
a spare or replacement drive when another drive in the array fails. This process is
also called
rebuild.
If a drive in a fault-tolerant configuration is replaced while the system power is off, a
Power-On Self-Test (POST) message is displayed during the next system startup.
This message prompts you to press the
F1
key to start Automatic Data Recovery. If
Automatic Data Recovery is not enabled, the logical volume remains in a ready-to-
recover condition and the same POST message is displayed whenever the system is
restarted.
When Automatic Data Recovery has finished, the Online LED of the replacement
drive stops blinking and begins to glow steadily.
In general, approximately 15 minutes is required to rebuild each gigabyte. The actual
rebuild time depends upon:
•
The level of rebuild priority that has been set for the logical drive
•
The amount of I/O activity occurring during the rebuild operation
•
The disk drive speed
•
The number of drives in the array (for RAID 5)
For example, the rebuild time when using 9-GB Wide-Ultra hard drives in a RAID 5
configuration varies from 10 minutes per gigabyte (for 3 drives) to 20 minutes per
gigabyte (for 14 drives).
Failure of Automatic Data Recovery
If the Online LED of the replacement drive stops blinking during Automatic Data
Recovery, there are three possible causes:
•
If the Online LED is glowing continuously, Automatic Data Recovery was
successful and has finished.