Use vmware Converter to Perform Live Windows Image Backup?

In Ch. 11 of Backup & Recovery I stated that there was no way to do a live image backup of Windows without spending money.  Turns out I was wrong!

I think EMC would love it if we eventually moved all physical servers into Vmware.  Toward that end, they have provided a free tool that you can use to to just that.  They call it the vmware converter, and you can use it to perform a live, image-level backup of a Windows system.  You can then use that backup to move your physical machine into a virtual machine.

The idea that I'm working on, though, is to use that imported virtual machine as a way to perform a free live bare metal backup & recovery of a Windows machine.  This idea was originally sent to me by JP Vossen, a fellow author and friend of the site.  I'm just doing the work to see how it can fit into my procedure.

I stated in Chapter 11 of Backup & Recovery that, without using commercial software, there was no way to create a live image of a running Windows system in a way that would allow us to use that image to recover that system from bare metal.  But through the wonder of vmware, I think we can.

Although this was surely not what the vmware designers had in mind when giving us free access to vmware server and converter, I think they'll be fine with it, because it demonstrates just how cool vmware is, even though we're only using it to backup and recover a physical machine.

Here's how it would/could/should work.  It's a bit clunky, but clunky is better than nothing.

  1. Use the P2V Converter to "import" your physical machine into a vmware virtual machine.  It can do this live, and it creates a file that will be the virtual machine's hard drive.
  2. Upon failure of the physical machine, boot the virtual machine that you imported with a knoppix CD.  This will give you access to the virtual hard drive in Linux (e.g. /dev/hda1)
  3. Now I have two theories.  The first theory is that as long as you told vmware to create a single virtual hard drive (not split it into 2 GB chunks) and to make the whole file at once, the .vmdk file it creates is a bit-level version of a hard drive that can be accessed without vmware.  If that's true, then during recovery, you would
    1. boot the system to be recovered into knoppix.
    2. Use dd to restore the vmdk file to the hard drive to be recovered (e.g. dd if=/nfsshare/vmware/machine.vmdk of=/dev/hda1 bs=126k)
    3. reboot
  4. If step 3 turned out not to be true, then you'd have to do it the hard way, as outline here.
    1. You'll have to do a two-step restore.  First dd the backup of the virtual hard drive to a file on a file share somewhere (e.g. dd if=/dev/hda1 of=/nfsshare/hda1.dd bs=126k)
    2. Now boot the machine you're restoring to from knoppix.
    3. Get access to the share where you stored the dd file.
    4. dd that file to the physical hard drive you're restoring (e.g. dd if=/nfsshare/hda1.dd bs=126 of=/dev/hda1)
  5. Reboot!

Now, all I need is a guinea pig!  Who wants to try this?

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Evangelist at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

4 thoughts on “Use vmware Converter to Perform Live Windows Image Backup?

  1. drock says:

    I think I have some spare systems around to play with this one. I’ll let you know what happens 😉

  2. dikrek says:

    But I believe VMware converter changes things while doing its migration. Worth a try, though.

  3. andrenoites says:

    I already tried that and it worked

    I have a server with 4x500Gb sata raid 5 with the server images and the O.S. windows 2003 server.

    In an emergency situation i simply run vmware server (free) and boot the image from the server i want.

    The phisical server must be down because the new virtual machine replicates de name and ip.

    Now im am trying to do is make diferencial backups based on the original image of the servers

  4. cpreston says:

    That’s what the tool was made for. (I”m glad to hear it does work, though.)

    The question is how much work is required to then take that image and copy it back to a live machine.

Comments are closed.