Dell PowerVault DL2000 - Manual (Page 36)

NOTE: For versions prior to Backup Exec 2012, see the topic "Recovering The Appliance System Disk Using IDR”.
For Backup Exec 2012 and later, see the topic "Recovering The Appliance System Disk Using SDR."
3. Recovering the Appliance System Disk without using IDR or SDR
4. Reinstalling The PowerVault DL Backup To Disk Appliance Applications
5. Repairing Dell OpenManage Server Administrator
6. Reinstalling Symantec Backup Exec During Disaster Recovery
7. DSF Recovery Solution Map
Recovering From Disk Failures
PowerVault DL2 xxx systems are automatically configured by the backup application in RAID groups to recover from disk
failures.
About RAID Types
The internal disk storage containing the operating system and applications in the DL2 xxx system is preconfigured as
RAID 1. RAID 1 is a mirrored disk group that provides uninterrupted operation of the appliance if a single disk fails within
that disk group.
CAUTION: A failed system disk must be replaced immediately to avoid data loss or complete failure of the
appliance.
The optional data disks in the PowerVault DL2100 and DL2200 systems and storage enclosures are automatically
configured by the backup application in RAID 5 or RAID 6 disk groups as described in the topic “Disk Configuration
Settings”.
NOTE: Automatic configuration only occurs if the disk configuration state is Standard and if you select one of the
automatic disk configuration policies. For more information see the topics “Disk Subsystem States” and “Disk
Configuration Policies”.
RAID 5 provides uninterrupted operation of the appliance if a single disk fails within that disk group. The RAID 5 standard
configuration includes a global hot spare in each storage enclosure and PowerVault DL2200 systems. If a single disk
failure occurs, the hot spare is automatically assigned and rebuilt into that disk group. After the disk group has been
rebuilt, the RAID 5 disk group continues to operate normally.
CAUTION: If another disk fails while the internal or external disk group is rebuilding, all data in that disk group is
lost. Always monitor the status of the disk rebuild of the appliance to ensure that the rebuild operation completes.
When the failed disk is replaced, the data residing on the global hot spare is automatically copied back to the
replacement disk. After the copy-back operation is complete, the global hot spare is once again available should
another disk fail. For more information about using global hot spares, see
Dell OpenManage Server Administrator User's
Guide at support.dell.com/manuals.
NOTE: Only one disk group per storage enclosure can utilize a hot spare at a time.
NOTE: There are no dedicated hot spares for internal disks in the DL2000 and DL2100 systems.
RAID 6 provides uninterrupted operation of the appliance if up to two disks fail within that disk group. Replacement of
the failed disk(s) causes the disk group to rebuild. If a third disk fails before the disk group rebuild is complete, data loss
occurs. The standard RAID 6 configurations do not include a hot spare.
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