DISCLAIMER: Disclaimer for anyone stumbling on this from the series-of-tubes-net…. The following steps are not exact and doing any of this could totally CORRUPT YOUR SYSTEM/DATA, so tread with caution or CLOSE YOUR BROWSER NOW.
So it seems I have seen this more than once in my life but have to relearn how to recover each time because it just isn’t commonly google-able. So blogging it here for my future self to reference later.
Software mirroring in Windows Server (2008 R2 for this exmaple) is great and all, but when you have a drive failure it isn’t very clear how to exactly recover.
Should the Secondary Drive (secondary plex its called) fail, it seems you will never notice it unless it happens to be making clicking noises or perhaps you diligently check your system logs for notifications of such things (I do not).
When the Primary Drive fails, it is pretty obvious – since your system won’t boot.
One would think that you simply need to open the PC and swap the SATA cables on your drives, but that doesn’t exactly work. In my most recent case, I was getting an error from Windows Boot Manager saying that a required device was not attached to the system (Like the Failed Drive? No kidding!). Instructions followed to Boot from a Windows DVD and do a REPAIR.
Okay I thought – I’ve done this before – easy enough….Except that the Windows Server 2008R2 Repair did not see my windows installation – which posed an obvious problem.
Okay, so the Boot Manager which I think is stored on the HARD DRIVE booted up enough to notice that something was missing, but then the Windows Repair process didn’t see the Drive.
There was an option to Load Drivers and I’ve had to do that before with special RAID controllers, but this was a plain ole SATA controller and drives on-board a Dell PC class system. No drivers to be loaded.
Just when I thought all was lost, I kept clicking around the repair options and got to a COMMAND PROMPT. Okay this is awesome I thought – let’s go to the command prompt check out the Windows Files and try a little FIXMBR action.
Except that the command prompt didn’t see my drive either.
To cut the story short for my future self the Real Key Here to Proceed was to run the DISKPART command from the command prompt… Next do some of these commands:
(The actual commands here may vary because I must have tried 20 different things before I got to a place that worked so use these as HINTS at best to solve your new problem):
SELECT DISK 0
SELECT PARTITION 3 (some crappy dell stuff on partition 0 and 1 apparently – the Windows one should be obvious by the size of it)
IMPORT ( The partition was listed as FOREIGN so needed to Import It)
ASSIGN ( Assign a Drive Letter to the PARTITION )
Could be more missing steps here
BREAK (This command breaks the MIRROR, but it didn’t work – instead gave me an error of MISSING PLEX)
You can also “Remove” the mirror(s) using Disk Management after you
get a successful boot. I removed the mirror from the “Missing Drive”
not the working one.
(Seriously No Kidding the PLEX is missing – I wouldn’t be at this command prompt if everything was still there and working)
LIST VOLUME (DO this to see what Drive Letter DISKPART has given your Windows Partition)
EXIT (Ultimately exit back to command prompt where you have the DRIVE letter showing up now)
Now back at command prompt make sure your New Drive Letter is there and you see your WINDOWS folder.
Be sure you’re on your newly found Windows Drive, J: in my case.
Now run the BOOTREC.EXE utility.
Here you can do the following:
Reboot your crap box and see if it all works. It did for me.
You will also want to lookup the BCDEDIT command to edit the bootup options. There may still be 2 options like “Windows 200x Standard” as well as a “Secondary Plex” option. BCDEDIT will allow you to remove the one that isn’t working and rename the “secondary plex” option since that will be the only one now.