Blowing up drive mirroring

On March 30, 2009, in sbs 2008, by

One of the cool things about having a HyperV test lab is that you can do things like blow up servers and it doesn’t matter.

So as a follow up I was asked about booting from the secondary drive when the primary fails. 

MirrorDynamicDisksServer2003 < NexusDocumentation < TWiki:

When I blew off the main C: drive on my HyperV test I was indeed able to boot into that secondary plex.  When you set up a software mirror you will note that you now get a new boot screen like so:

Now let’s test that the system will work from the mirror.

We’re just going to nuke that drive.

Once we nuke the disk we will select the secondary drive option to test the boot up.

If we’d let it boot from the first drive, it would fail.

But if we choose Windows 2008 – Secondary Plex by scrolling down to it and choosing it as the bootable option, we can boot the box.

Select the secondary plex and the box will boot even though we’ve just blown off the main drive.

Remember we just nuked the hard drive and the system is still booting up.

When we log in we find that we are missing a drive.  (remember I removed it from the HyperV setup but the vhd is still on the computer undeleted)

As you can see it’s booted up but it knows it’s not a happy camper.

Okay so now let’s test putting that drive back online.

In our HyperV test, we’re going to go back into the settings and add that existing vhd back.  We click on New and then copy the location back in and click ok.

We turn it back on and let it boot back as it was.

We will have an unhappy camper in Disk Management, so make sure you go back and fix the mirror. 

You can’t reactivate the missing disk you have to import the foreign disk.

Choose the mirrored drive and set the mirror back up as it should be.

Now back to happy campers.

Now I’m sure you’ll ask but what if you need to blast off the original drive.  No prob, you just go into the boot.ini file and edit out the so that the system boots from the main drive, then you rebuild the mirror with a new disk. 

Alternatively you can use fixmbr – and that will set up a new boot record.

Bottom line, get a box, load up a hyperV, build a SBS and start blowing things up.



One Response to Blowing up drive mirroring

  1. John says:


    Thank you very much for taking the time to do this and report the results!


    (P.S. I have thought that if they remake “The Graduate”, instead of telling the Hoffman character “Plastics” a modern version would have him being told “Virtualization”!)