Installation manual

47 ATTO Technology Inc. ATTO Utilities Installation and Operation Manual

Recovery Mode

Sometimes, despite careful operation and

maintenance, drives will coincidentally fail in such a

way that the RAID Group integrity is compromised.

After a RAID Group has been marked OFFLINE

because of problems with member drives, there is a

way to possibly recover some of the data. The

following guidelines and commands can help recover

data from an OFFLINE RAID Group. The following

descriptions refer to RAID 5 specifically, but the

principles extend to other RAID types.

Recovery from Failed Rebuild

Fault During Rebuild - Recover by Forcing Rebuild

to Continue

Note

The diagrams which follow illustrate a

scenario where a failed drive is removed and

replaced. The error recovery procedure is

also valid if there is a Hot Spare, or if there is

an unallocated drive and Auto Rebuild is

enabled.

Exhibit 1.4.1--24 RAID 5 Group with 4 Operational

Drives

Exhibit 1.4.1--25 A Drive Fails; RAID Group goes

DEGRADED

Exhibit 1.4.1--26 Drive is Removed and Replaced

Exhibit 1.4.1--27 Media Error During Rebuild; Rebuild

Halts, RAID Group goes OFFLINE

Use the ATTO ConfigTool to force the RAID Group to

continue the rebuild. First, display the RAID Group

information as shown in

Exhibit 1.5.1--18

. Then right-

click on the Offline RAID Group that has the Rebuild

status

Rebuilding (Faulted)

. Select the option Start

Recovery Rebuild as shown below in

Exhibit 1.5.1--

1 2 3