HP Smart Array P400 doesn´t recognize member of mirror

[Ries]

I have one memberdisk of a mirrored array (the other one was broken). This disk was taken from the server and placed on a shelf until the new disk would arrive.
If I place this disk into the server again (together with the new disk) to recover the mirror, the array controller doesn´t recognize it to be member of a former raid but treats it as new disk.
How can I recover the mirror or (at least) recover my data?
Thanks for ideas.

[Ken Henault · Accepted solution]

Turn the computer on with no disks in the system. Go into the array configuration during POST and clear any configuration. Power the system off. Insert just the disk with data, and power the system on. The array should read the meta data from the disk and recreate the array configuration. You may see an error telling you that the array is degraded, because you only have one member of the mirror set. Let the OS boot, then insert the blank disk, the mirror set should rebuild.