Preference; Disk Lag Proof Mode - Accusys ExaSAN User Manual

4.1.6 Preference

This feature ensures the stability and continuity of the RAID performance. In RAID 5 and RAID
6, DLP prevents the aging or slow responds of a single hard disk from influencing the overall
performance. The advantage of this feature will not be felt until some hard disks fail to perform
well.
In the event of performance degradation or delay of a single drive due to aging, the ExaSAN
RAID system reads both data and parity stripes concurrently. It bypasses the slow reads and
returns data to the host with the regenerated data and to provide stabled performance based on
the RAID parity.
Note
Although slow responds of some hard disks can be tolerated in DLP
mode, you may use S.M.A.R.T. function to check the conditions of hard
disks in an array and replace the faulty ones.
Note
This function does not support JBOD and NRAID.
User Guide

4.1.6.1 Disk Lag Proof Mode

DLP concept
5. RAID