Controlling the performance impact of RAID data reconstruction

If a disk fails, the data on it is reconstructed on a hot spare disk if one is available. Because RAID data reconstruction consumes CPU resources, increasing the speed of data reconstruction sometimes slows storage system network and disk operations.

Considerations

When RAID data reconstruction and plex resynchronization are running at the same time, Data ONTAP limits the combined resource utilization to the greatest impact set by either operation. For example, if raid.resync.perf_impact is set to medium and raid.reconstruct.perf_impact is set to low, the resource utilization of both operations has a medium impact.

Step

Enter the following command: options raid.reconstruct.perf_impact impact
impact can be high, medium, or low.

high means that the storage system uses most of the system resources—CPU time, disks, and disk-to-controller bandwidth—available for RAID data reconstruction; this setting can heavily affect storage system performance.

low means that the storage system uses very little of the system resources; this setting lightly affects storage system performance.

The default speed is medium.

Note: The setting for this option also controls the speed of Rapid RAID recovery.

Parent topic: Controlling the impact of RAID operations on system performance

Controlling the performance impact of plex resynchronization

Controlling the performance impact of mirror verification