Raid Settings - Overland Storage SnapServer Administrator's Manual

SnapServer 7.0 Administrator's Guide

RAID Settings

Click the RAID Settings button on the RAID Sets page to allow you to enable or disable the
automatic incorporation of a disk into a degraded RAID set or a background scan.
Automatic Incorporation of Hot-Swapped Drives
If a RAID (except RAID 0) is running in degraded mode and a raw drive, a non-GuardianOS
drive, or an unassigned GuardianOS-partitioned drive is "hot-inserted" into a SnapServer,
it can be automatically assigned as a local spare and used to rebuild the degraded RAID. If
there are no degraded RAIDs, a hot-inserted non-GuardianOS or unassigned drive will be
automatically configured as a global spare. To enable automatic incorporation of
unassigned drives, go to the Storage > RAID Sets page and click the RAID Settings button.
NOTE: Drives that have previously been used in a different system are not automatically
Background Disk Scan
The background disk scan checks the integrity of RAID data by continuously scanning the
disk drives for errors. Each RAID (except RAID 0) has its own background disk scan that is
set to run when the I/O activity falls to a very low disk activity. Once the activity rises above
the idle threshold, the background scan stops and waits for the activity to fall to the idle
threshold again before resuming. As a result, there should be minimal to no impact on
performance. Once the disk scan has completed a pass on a given RAID set, it waits a
designated period of time before starting again.
The background disk scan is enabled by default. To disable the background disk scan, go to
the Storage > RAID Sets page and click the RAID Settings button. Note the following:
• If the background disk scan is disabled, the SnapServer will still initiate a scan on a
RAID if problems are detected on one of the RAID drives.
• The background scan will not run on RAIDs that are degraded, syncing, or rebuilding.
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incorporated, regardless of whether automatic incorporation of unassigned drives is
turned on. You must manually incorporate and configure these drives.
©2010-11 Overland Storage, Inc.
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