Dell PowerVault DL2000 - Manual (Page 37)

Detecting And Monitoring Disk Failures
To optimize the protection of the RAID configured storage on the appliance, it is essential that you detect hard disk
failures immediately. Replacing failed disks immediately reduces the risk of unplanned downtime and loss of critical
data.
You can use the following methods to monitor the health of the disks:
• Hard-drive LED indicators—Each drive in the server and storage enclosure contain status LEDs to indicate drive
activity and certain failure status. See the Owner’s Manual for the server and storage enclosures at
support.dell.com/manuals.
• Dell OpenManage Server Administrator—Server Administrator monitors the health of both internal and external
direct-attached disks. For more information, see the topic "Replacing Disks".
• Dell Management Console (DMC)—DMC centrally monitors the status of the Dell systems. For information about
installing and using DMC, see the Dell Management Console User’s Guide at support.dell.com/manuals.
Recovering From Single Disk Failures
After you replace a failed disk drive within a RAID group, the appliance automatically rebuilds the disk group. The data
on the virtual disks in the disk group is still available to the system and the system runs without any interruption. The
appliance operates in degraded mode until the rebuild operation is complete.
CAUTION: If an additional disk fails in the same RAID 1 or RAID 5 disk group during the rebuild operation, data loss
occurs.
Use Server Administrator to monitor the progress and status of the RAID rebuild. If the rebuild does not begin
automatically, see the topic “Rebuild a Failed Physical Disk” in
Dell OpenManage Server Administrator User’s Guide at
support.dell.com/manuals to initiate the rebuild manually. Server Administrator reports the status and progress of a
rebuilding RAID group.
Recovering From Multiple Disk Failures
Data loss occurs if both disks in RAID 1 group on the server fail, two or more disks in a RAID 5 group fail, or three or
more disks in a RAID 6 group fail. After replacing the failed disks, depending on which RAID group failed, choose from
the following methods to complete recovery:
• Server disk group failure—The server RAID 1 group contains the operating system, backup application, and the
DL Backup to Disk Appliance applications. See the topic "Recovery Solution Map" and follow the steps for the
operating system failure type. If the optional internal backup data RAID disk group fails, follow the procedure
below for storage array disk group failure.
NOTE: It is recommended that you use the IDR or SDR that is part of Symantec Backup Exec software to recover
the system in the event of a server software or hardware failure. See the topic "Recovery Solution Map" for the
specific recovery methods.
NOTE: After replacing the appliance's internal operating system disks, ensure that the appropriate virtual disk is
selected as the Boot VD.
• Storage array disk group failure—You can restore the backup sets archived to tape or from a secondary
appliance protecting the primary appliance. For more information about disaster planning recovery procedures,
see the “Disaster Preparation And Recovery” section of the Symantec Backup Exec Administrator’s Guide at
symantec.com.
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