If all elements of a mirrored RAID report a status of “not in sync”, use the following procedure to recover the mirror.
Determine which element you believe to be the in-sync element.
Log in to the server as the root user, and open a terminal console.
Launch nssmu.
From the NSSMU menu, select Software RAIDs.
In the list of RAIDs, select the RAID, then press Enter to see its elements.
Remove all of the elements from the mirror except the element you want to keep. Select the element to delete, then press Delete. Repeat this step for each of the elements you want to remove from the Software RAID. Wait for the segment to be removed before you remove the next segment.
When you are done, you have a RAID1 device that consists of the single element that you believed to be the in-sync element.
Force the single RAID element to be in sync. On the Software RAIDS page, select the RAID device, then press F6 (Restripe).
Add elements back into the mirror as desired.
On the Software RAIDs page, select the RAID device and press F3 (Expand).
From the list of available devices, select the device or devices that you want to add.
Press F3 (Accept).