Windows Update broke my RAID!

[#1]

I have a pair of 1TB HDD's in my Windows 7 x64 PC, configured as a RAID 1 (mirrored) array. After restarting following installation of the April Windows Updates yesterday, the RAID controller POST message warned of a critical error with one of the disks. On checking via the Storage function in Control Panel/Admin. Tools, I discovered that a disk had been taken offline, the stated reason being a 'signature collision'. There appeared to be a new partition on this disk which was not present on the other, the reason for which is unclear.

After several hours of head-scratching I was able to rebuild the array using AMD RAIDXpert; although a HDD fault was obviously a possibility, the fact the error occurred immedately after applying the Updates (and has not appeared since, touch wood!) suggests that some component of the Windows Update was responsible. I have previously had the MBR damaged and the system rendered unbootable by a Windows Update a year or so back.

Unfortunately I can't identify which of the Updates caused the issue; this is made more difficult anyway by MS's recent practice of bundling them all together, rather than releasing as individual KB's. I also (perhaps foolishly) chose to install the optional 'preview' Update, so perhaps something there isn't ready for prime time.

Anyway, I relate this as a warning to anyone with a similar RAID setup!

[#2]

Take a full backup before running any Windows updates.

[#3]

@NorthPole I'm not convinced that the updates had anything to do with what happened, I think if anything it was bad timing or sod's law if you're a member of the society. As you'll know a setup like yours presents a single disk to the OS and you may well have the signature collision as a result of the disk faulting as Windows expects these to be unique for booting purposes.

You may want to run disk diagnostics over your array just to be on the safe side, and maybe a few stress test if you can, as this may not be the last you see of this error.

[#4]

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@VileReynard wrote:

Take a full backup before running any Windows updates.

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I always do - once bitten etc.

[#5]

A few weeks ago I set an Apple mac to upgrade its OS to the latest version from about 3 versions behind.  It failed and got stuck in a start-up loop because there was some hard disk problem that none of the Apple tools could fix.  I had to back-up, wipe the disk and re-install the OS.  Did the upgrade break the disk or did the stress of applying the upgrade reveal a pre-existing problem that had not otherwise manifested?  I don't know the answer but it seems analogous to what is reported here (even without the RAID involvement).     

[#6]

Your 3 versions old was too old for the upgrade.

Read any documentation - I wouldn't expect to be able to upgrade any OS through 3 versions in one go!

I would think its a case of asking too much of the software.

[#7]

Remember this was Apple, Jeremy.  They bring our a new version of their OS about once a year.

[#8]

Well, I finally got round to running a surface check on the suspect disk with RAIDXpert (it seems to be the equivalent of using chkdsk /r on a single disk); but it threw up no issues at all. Not a job you want to babysit either; it took over 24 hours!

So my money is still on Windows Update being the cause of the problem; or less likely, some hardware problem with the RAID or disk controller. But at least I now know the computer will run pro tem with just one disk of the pair operative, and that I can rebuild the array if required.