Dell EqualLogic PS-M4110 - Array Behavior When a Drive Fails

Dell EqualLogic PS-M4110 Hardware Owner's Manual Chapter 3 Maintaining Drives
• Indications in the Group Manager Member Disks window
• The output of the member select show disks command in the CLI.
Interpreting Drive LEDs
The LEDs on a drive are shown in Figure 18. Drive LED states are described in Table 4.
Figure 18: Drive LEDs
Table 4: Drive LED States
Callout LED Name Description
1
ACT (Drive activity) Blinking green: Drive is busy
Steady green: No drive activity
Off: No power to drive
2
STAT (Power state) Green: Drive OK
Amber: Drive failed
Off: No power to drive
Array Behavior When a Drive Fails
How an array handles a drive failure depends on whether a spare drive is available and whether the RAID set
containing the failed drive is degraded.
For example:
• If a spare drive is available, the array automatically uses it to replace the failed drive. Performance is nor-
mal after reconstruction completes.
• If a spare drive is not available, the RAID set will become degraded (except a RAID 6 set). Performance
may be impaired. A RAID 6 set can survive two simultaneous drive failures.
• If a spare drive is not available, and the failed drive is in a RAID set that is already degraded, data may be
lost and must be recovered from a backup.
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