Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm working with Windows Server 2008 Web Edition SP1 on a dedicated box (with KVM access). As soon as I convert the system disk (C) to dynamic and reboot I get this message: Error loading operating system. I'm converting the disk to dynamic so that I can mirror the system drive with a second drive. I've actually went through the mirroring process before, everything works fine until I reboot. Could a simple conversion to dynamic stop the system from loading? Although this smells like a software issue, could it be hardware related? Any suggestions?


Hardware: SuperMicro H8SMU (motherboard), AMD Opteron 1216HE, 4GB RAM, 2 x WD Caviar RE 16 WD2500YS.

share|improve this question

It sounds like the disk is being put into an unreadable/offline/not-initialized state...

One solution, if possible, is to pull the disk out and plug it into another Win OS which support dynamic disks (all pro/business/server editions of Windows since XP) and take a look at the disk in the Disk Management snap-in. If the disk is merely offline and can be activated inside that operating system, then it is likely an issue with how the Dynamic Disk MBR is being processed on boot. (Potentially hardware related.) (Also, you may need to import the disk into the other environment.)

If the disk appears as 'Unreadable' then WS2008 probably messed up the conversion process.

Could you give us a few details about the hardware you're running on? Dynamic disks occasionally do not jive with particular varieties of onboard RAID.

See Also:

Hope this is useful :)

share|improve this answer
I've edited the post to include the hardware info. Unfortunately I don't have physical access to the server, and the hosting company says they don't support software RAID. I don't think it's a hardware issue because everything works fine until the disk is converted to dynamic. I can't activate the disk because it's the disk that has the OS the one with the problem. Thanks. – pbz May 6 '09 at 3:18
How did you have the two disks setup prior to converting disk0 (I'm just going to call your C: drive that) to dynamic? The disks are not already mirrored in any way, are they? All you did was to convert disk0 to dynamic?? – ParoX May 6 '09 at 3:51
" All you did was to convert disk0 to dynamic?" -- That is correct. Prior to converting they were basic. We decided to upgrade to hardware RAID as I couldn't get the software one to work. – pbz May 7 '09 at 22:12
So just to be clear: you've given up on the dynamic disk thing and are now opting for hardware RAID instead? Or were you trying to implement HW RAID using dynamic disks?? – ParoX May 8 '09 at 4:48
After about two days of unsuccessfully trying to make software RAID to work we had to give up and upgrade to hardware RAID. So, while I was trying to get software RAID to work, and implicitly convert the system disk to dynamic, there was no hardware RAID in sight. After we got the hardware RAID there was no need to convert to dynamic, we actually only see it as one disk in Windows. Thanks. – pbz May 8 '09 at 17:53

It sounds like converting it to a dynamic disk screwed up your Master Boot Record.

share|improve this answer
Any way I could convert the system disk to dynamic without it crashing? This is the second time it happened, so I don't think it's a fluke, more like I'm doing something wrong. – pbz May 6 '09 at 0:37
up vote 0 down vote accepted

We ended up using hardware RAID

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.