A. Mikkelsen VMware ESX scripts, commands, tools and other nice to know things that will make your virtualization days easier!!!!

Friday, November 19, 2010

Downgrading ESX virtual hardware 7 to 4

When you upgrade your vSphere environment you normally also upgrade the VM’s virtual hardware to version 7, to take advantage of the new features. This is pretty normal procedure for all VMware admins.

But in some very very rare cases you might need to move a VM upgraded to hardware version 7, to a host that doesn’t support VM’s running hardware version 7.
From a host running ESX 4.x to a host running ESX 3.x

So what to do.
There is two ways you can accomplice this task.

The first way is to use the free VMware Converter tool.
Some great guides have been created by others so I don’t want to do it all over again.
The only thing is that it can take some time to convert the VM, but it is a proven and stable method.

The other way is to do it manually, this way is a lot faster, but there is a risk that it will corrupt the VM, so make sure you have a working backup.
Use this guide on your own risk

  • Powered off the VM
  • Make sure the VM doesn’t have any snapshots before proceeding
  • From the ESX console or from a Putty session, edit the VMs VMX file, using your favorite editor
    vi /vmfs/volume/DS1/WIN2008-001/WIN2008-001.vmx
  • Change the virtual hardware version from:
    virtualHW.version = “7”


    virtualHW.version = “4”
  • You don’t need to change config.version = “8”, since ESX 3.x already uses this version
  • Change the virtual controller, because virtual hardware version 4 doesn’t understand the version 7 virtual controller, from:
    scsi0.virtualDev = “lsisas1068”


    scsi0.virtualDev = “lsilogic”
  • From the ESX console or from a Putty session, edit the VMs VMDK pointer file/files (if more than one virtual disk), using your favorite editor
    vi /vmfs/volume/DS1/WIN2008-001/WIN2008-001.vmdk
  • Change the virtual hardware version from:
    ddb.virtualHWVersion = "7"


    ddb.virtualHWVersion = "4"
  • You should now be able to power on the VM as virtual hardware version 4.


  1. Superb!! Been looking around for how to convert from 7 to 4 manually – converter’s OK, but can take an age when you have VM’s with large disks. Hacking the vmx and vmdk files is the way to go for me!!

    Comment by Dan — Monday, July 18, 2011 @ 9:20 am

  2. Always glad to be able to help.

    Comment by A. Mikkelsen — Monday, July 18, 2011 @ 12:12 pm

  3. how do you edit a 96 gig *.vmdk file on the last step? Am I missing something?

    Comment by dave — Thursday, August 4, 2011 @ 21:45 pm

  4. Hi,
    You only edit the *.vmdk file and not the *-flat.vmdk file.
    The flat file is the 96 Gb one the other is only a few KB.

    Remember this only works on ESX or ESXi not on WRK or Server.

    A. Mikkelsen

    Comment by A. Mikkelsen — Tuesday, August 9, 2011 @ 12:07 pm

  5. Has anyone tried coverting virtual hardware 8 to 7 using the above method?

    Comment by Alan — Thursday, December 1, 2011 @ 9:54 am

  6. Not yet,
    Haven’t had time or thought about it….

    But like to know if it works 🙂

    A. Mikkelsen

    Comment by A. Mikkelsen — Thursday, December 1, 2011 @ 10:30 am

  7. Great web site. Lots of helpful info here. I’m sending it to some pals ans also sharing in delicious. And naturally, thank you to your effort!

    Comment by interesting blog — Friday, February 3, 2012 @ 10:33 am

  8. Hi, its worked for my debian 6 system. Downgraded from Vsphere 5 to Vsphere 4.

    Thanks Mikkelsen.


    Comment by Kumar — Friday, July 13, 2012 @ 14:23 pm

  9. Hi,
    Glad it worked.

    A. Mikkelsen

    Comment by A. Mikkelsen — Friday, July 13, 2012 @ 15:10 pm

  10. I really need to convert a vm template which was sent to me with v8 HW to a v7 HW to get it working on a vSphere 4.1

    Comment by Luke — Tuesday, September 25, 2012 @ 23:54 pm

  11. Hi Luke,
    The guide also works on downgrading vHW8 to vHW7.
    I haven’t tested it on a template, but it should work.
    Just remember to take a copy of the template, prior to changing the vHW.

    A. Mikkelsen

    Comment by A. Mikkelsen — Wednesday, September 26, 2012 @ 6:34 am

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