Disk and File System Management 3-3
8VH'LVN6FUXEELQJWR3URWHFW'DWD)URP0HGLD(UURUV
The filer uses the RAID disk scrubbing procedure to increase data availability. The filer
scans each disk in the RAID group for media errors. If the filer finds media errors, it
fixes them by reconstructing the data from parity and rewriting the data.
Disk scrubbing reduces the chance of a multiple disk failure, caused by a disk media
error encountered while the system was running in degraded mode.
The filer only scans a RAID group when all the groups disks are operational. Although
disk scrubbing slows the filer somewhat, network clients might not notice the change
in the filers performance because disk scrubbing starts automatically at 1:00 A.M. on
Sunday, when most systems are lightly loaded.
By default, disk scrubbing is enabled. You might want to disable scrubbing if you have
a recurring problem that scrubbing encounters.
Example: For example, there might be an unrecoverable error on a disk that you can-
not fix before the next disk scrub. The following commands disable and enable disk
scrubbing:
RSWLRQVUDLGVFUXEHQDEOHRII
RSWLRQVUDLGVFUXEHQDEOHRQ
Commands to start and stop disk scrubbing: You can also manually start and
stop disk scrubbing regardless of the current value (On or Off) of the
raid.scrub.enable option. Following are the commands for starting and stopping
scrubbing manually:
GLVNVFUXEVWDUW
GLVNVFUXEVWRS
Sample messages logged from scrubbing: Messages from the disk scrubbing pro-
cess are sent to the system error logging daemon.
Following are sample messages that can appear:
If the filer finds an inconsistent parity block during scrubbing, it prints the follow-
ing messages:
,QFRQVLVWHQWSDULW\RQYROXPHYROXPHBQDPH5$,'JURXSQ
VWULSH Q
5HZULWLQJEDGSDULW\EORFNRQYROXPHYROXPHBQDPH5$,'JURXS
QVWULSH Q
NOTE: An

Inconsistent parity

error message might indicate file system
corruption. If you get such an error, contact Dell technical support for assistance.
If the filer finds a media error on the parity disk, it prints the following message:
5HZULWLQJEDGSDULW\EORFNRQYROXPHYROXPHBQDPH5$,'JURXS
QVWULSHQ