Disk scrubbing means checking the disk blocks of all disks on the storage system for media errors and parity consistency. If Data ONTAP finds media errors or inconsistencies, it fixes them by reconstructing the data from other disks and rewriting the data. Disk scrubbing reduces the chance of potential data loss as a result of media errors during reconstruction.
Data ONTAP enables block checksums to ensure data integrity. If checksums are incorrect, Data ONTAP generates an error message similar to the following:
Scrub found checksum error on /vol/vol0/plex0/rg0/4.0 block 436964
If RAID4 is enabled, Data ONTAP scrubs a RAID group only when all the group's disks are operational.
If RAID-DP is enabled, Data ONTAP can carry out a scrub even if one disk in the RAID group has failed.
This section includes the following topics:
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Last updated: 01-Dec-2005 16:51:31