Features
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Compaq Smart Array 5i Plus Controller User Guide
COMPAQ CONFIDENTIAL
Writer: Amy L. Laffitte File Name: b-ch.1-features
Codename: Executor Part Number: 266328-001 Last Saved On: 4/18/02 2:33 PM
See Appendix C, “Drive Arrays and Fault Tolerance,” for general information about
drive arrays.
Fault Management Features
The array controller and the network operating system support several fault
management and data reliability features that minimize the impact of hard drive
defects on your system.
•
Auto Reliability Monitoring
(ARM) is a background process that scans hard
drives for bad sectors in fault-tolerant logical drives. ARM also verifies the
consistency of parity data in logical drives that are using RAID 5. This process
assures that you can recover all data successfully if a drive failure occurs in the
future. ARM operates only when you select RAID 1 or RAID 5.
•
Dynamic sector repair
by the controller automatically remaps any sectors that
have media faults (detected either during normal operation or by auto reliability
monitoring).
•
Drive parameter tracking
monitors more than 15 drive operational parameters
and functional tests, allowing the array controller to detect drive problems and
predict drive failure before it occurs. This feature makes possible the Compaq
Pre-Failure Warranty on Compaq hard drives.
Parameters that are tracked include read, write, and seek errors; spin-up time;
cable problems; and functional tests such as track-to-track seek time, and one-
third stroke, and full-stroke seek time.
•
Drive failure alert features
cause an alert message to be displayed on the
system monitor when drive failure occurs. Different Compaq server models use
different messages for different situations. These messages are described in your
server documentation.
•
Interim data recovery
occurs if a drive fails in fault-tolerant configurations
(RAID 1 or RAID 5). In this situation, the system will still process I/O requests,
but at a reduced performance level. Replace the failed drive as soon as possible
to restore performance and full fault tolerance for that logical drive. Otherwise, if
another hard drive fails before data has been rebuilt, the logical volume will fail
and data will be lost. See Appendix D for more information about recovering
from drive failure.
