Hard Drive Installation and Replacement

•RAID ADG configurations can tolerate simultaneous failure of two drives.

If more hard drives fail than the fault-tolerance method allows, fault tolerance is compromised and the logical drive fails. In this case, all requests from the operating system are rejected with unrecoverable errors. The “Compromised Fault Tolerance” section discusses possible ways to recover from this situation.

Recognizing Drive Failure

The LEDs on the front of each hard drive are visible through the front of the server or external storage unit. When a drive is configured as a part of an array and attached to a powered-up controller, the status of the drive can be determined from the illumination pattern of these LEDs.

Table E-1describes the meaning of the various LED combinations.

1 2

3

Figure E-1: Hard drive status LED indicators

E-2

HP Smart Array 641/642 Controller User Guide