Promise Technology 15110 Critical & Offline Disk Arrays, When a Disk Drive Fails, Rebuild

VTrak 15110 User Manual

Critical & Offline Disk Arrays

A fault-tolerant disk array—RAID 1, 3, 5, 10 and 50—goes critical when a drive is removed or fails. Due to the fault tolerance of the disk array, the data is still available and online. However, once the disk array goes critical, the disk array has lost its fault tolerance, and performance may be adversely affected.

If the fault was caused by a failed drive that was removed, the drive must be replaced by another drive, either identical or larger, in order for the RAID system to rebuild and restore optimal configuration.

If your fault-tolerant disk array goes offline, go to the Promise website (www.promise.com) and download a document called Array Recovery Procedure.

A non-fault tolerant disk array—RAID 0—goes offline when a drive is removed or fails. Since the disk array is not fault tolerant, the data stored in the disk array is no longer accessible.

If one disk drive fails, all of the data on the disk array is lost. You must replace the failed drive. Then, if the disk array had more than one disk drive, delete the disk array and re-create it. Restore the data from a backup source.

When a Disk Drive Fails

VTrak provides both audible and visual indicators to alert you of a disk drive failure. The following will occur when a disk drive fails or goes offline:

•The Disk Array LED changes from green to amber

•The Disk Carrier Status LED changes from green to red

•The audible alarm repeatedly sounds two short beeps

•WebPAM PRO and the CLU report the condition

Rebuild

Normally, the disk array will begin rebuilding automatically. You can access your disk array during this time but read/write performance might be slower than normal.

•If a hot spare drive is provided and enabled, the controller will activate the hot spare and rebuild disk array information and data to it.

•If there is no hot spare drive available, the controller will wait until a replacement disk drive is installed. The disk array will remain Critical.

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