Health metrics

The disk hospital maintains the following internal health assessment metrics for each pdisk. When one of these metrics exceeds the threshold, the pdisk is marked for replacement according to the disk maintenance replacement policy for the declustered array.

relativePerformance

Characterizes response times. Values greater than one indicate that the disk is performing above average speed; values less than one indicate that the disk is performing below average speed. Values within a range of 0.800 to 1.250 are considered normal. Examples of typical values are: 0.932, 0.978, 1.039, and 1.095. If the relativePerformance of a disk falls below a particular threshold (the default setting is 0.667), the hospital adds slow to the pdisk state, and the disk is prepared for replacement.

dataBadness

Characterizes media errors (hard errors) and checksum errors.