Manually running a disk scrub

About disk scrubbing and checking RAID group parity

You can manually run disk scrubbing to check RAID group parity on RAID groups at the RAID group level, plex level, or aggregate level. The parity checking function of the disk scrub compares the data disks in a RAID group to the parity disk in a RAID group. If during the parity check Data ONTAP determines that parity is incorrect, Data ONTAP corrects the parity disk contents.

At the RAID group level, you can check only RAID groups that are in an active parity state. If the RAID group is in a degraded, reconstructing, or repairing state, Data ONTAP reports errors if you try to run a manual scrub.

If you are checking an aggregate that has some RAID groups in an active parity state and some not in an active parity state, Data ONTAP checks and corrects the RAID groups in an active parity state and reports errors for the RAID groups not in an active parity state.

Running manual disk scrubs on all aggregates

To run manual disk scrubs on all aggregates, complete the following step.

Step	Action
1	Enter the following command: aggr scrub start

You can use your UNIX or CIFS host to start a disk scrubbing operation at any time. For example, you can start disk scrubbing by putting disk scrub start into a remote shell command in a UNIX cron script.

Disk scrubs on specific RAID groups

To run a manual disk scrub on the RAID groups of a specific aggregate, plex, or RAID group, complete the following step.

Step	Action
1	Enter one of the following commands: aggr scrub start name name is the name of the aggregate, plex, or RAID group.

Examples

In this example, the command starts the manual disk scrub on all the RAID groups in the aggr2 aggregate:

aggr scrub start aggr2

In this example, the command starts a manual disk scrub on all the RAID groups of plex1 of the aggr2 aggregate:

aggr scrub start aggr2/plex1

In this example, the command starts a manual disk scrub on RAID group 0 of plex1 of the aggr2 aggregate:

aggr scrub start aggr2/plex1/rg0

Stopping manual disk scrubbing

You might need to stop Data ONTAP from running a manual disk scrub. If you stop a disk scrub, you can not resume it at the same location. You must start the scrub from the beginning. To stop a manual disk scrub, complete the following step.

Step	Action
1	Enter the following command: aggr scrub stop aggr_name If aggr_name is not specified, Data ONTAP stops all manual disk scrubbing.

Suspending a manual disk scrub

Rather than stopping Data ONTAP from checking and correcting parity, you can suspend checking for any period of time and resume it later, at the same offset when you suspended the scrub.

To suspend manual disk scrubbing, complete the following step.

Step	Action
1	Enter the following commands: aggr scrub suspend aggr_name If aggr_name is not specified, Data ONTAP suspends all manual disk scrubbing.

Resuming a suspended disk scrub

To resume manual disk scrubbing, complete the following step.

Step	Action
1	Enter the following command: aggr scrub resume aggr_name If aggr_name is not specified, Data ONTAP resumes all suspended manual disk scrubbing.

Viewing disk scrub status

The disk scrub status tells you what percentage of the disk scrubbing has been completed. Disk scrub status also displays whether disk scrubbing of a volume, plex, or RAID group is suspended.

To view the status of a disk scrub, complete the following step.

Step	Action
1	Enter one of the following commands: aggr scrub status aggr_name If aggr_name is not specified, Data ONTAP shows the disk scrub status of all RAID groups.