Stubborn Foreign Disk on PERC 710 raid controller

Question

I have a server that crashed (don't know why) and it lost access to most of its 24 drives. The server needed a full power cycle to make the disks show up again, except one disk needed a second go (was unplugged and reinserted). Now, while some of the virtual disks went into background initialization, one virtual disk had to rebuild a mirrored disk, and one virtual disk completely lost one of its mirrored disks (the disk that was removed and reinserted, but it was lost before the removal). When I say lost, the raid controller could not see the disk at all.

Now, with the physical disk visible (disk 0:12), can see it is now gone into the Foreign state. And I can't do anything about it (or so it seems). This is my list of tools:

• iDRAC
• OMSA
• omconfig/omreport
• MegaCLI

The controller is an PERC H710P Mini (Embedded) in a Dell R720xd server.

I tried clearing the foreign configuration this way:

• iDRAC: Does not see any foreign configuration on the controller even though it displays the physical disk as foreign.
• OMSA: When I try to open Foreign Configuration options page, it claims there are no foreign configurations. But according to physical disk view, disk 12 is foreign.
• omconfig storage controller action=clearforeignconfig controller=0 fails after like 1-2 minutes blocking IO with: Failure!
• omconfig storage pdisk action=clear controller=0 pdisk=0:12 fails fast with Operation not supported. Read, action=clear
• MegaCli64 -CfgForeign -Scan -aAll reports after 1-2 minutes There are 1 foreign configuration(s) on controller 0.
• MegaCli64 -CfgForeign -Clear -a0 fails after 1-2 minutes with Failed to clear Foreign configuration on controller 0., exit code 0x01.

How can I get this disk operational again? I must have missed something...

Answer 1

I discovered that MegaCLI has been superseeded by perccli, so I downloaded that, figured out how to use it, and this actually worked! This is what I did:

I deleted the foreign configuration with this command:

perccli64.exe /c0/fall del

Then I assigned disk 12 as hotspare to drivegroup 3 (could probably have chosen global hot spare):

perccli.exe /c0/s12 add hotsparedrive dgs=3

Both commands cause IO to stop for a couple of minutes so be prepared for that, but both commands completed successfully and the controller is rebuilding the array as I type this.

Success!