Migrating VMs : don’t use OVA/OVF?

Don’t use OVF to move virtual machines around in your environment?

Interesting thread here, http://communities.vmware.com/message/2110421

Where resident expert continuumsuggests not using OVF to move vms around.

Instead he suggests taking the files in the folder,  (vmdk, vmx, vmxf) and moving them to their new location.

Here is why:

OVF-export reads the existing vmx-file and tries to guess which parameters are important. Then it obscures the content of the original, drops some parameters and writes the result into an xml-file.

OVF-import again reads the xml-file and tries to guess which parameters are important. Again it may drop some parameters and then it creates a new vmx-file.

I just made a test: all on the same platform.

the original vmx had 85 lines - after export and re-import the new vmx-file has only 59 lines - 5 of those lines were added that did not exist in the original.

The final result:

the MAC address was lost and the PCI-slots of the VM were re-arranged.

several custom parameters were completely lost

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The result may still work but it definetely is a different VM than the one I exported.

On a Windows VM the result may require a new activation.

More picky guests may not even boot anymore.

Why would you want to do that ???

Ok - you may have a large thick provisioned vmdk - too large to copy it as it is.

Then use vmkfstools -i to clone the existing vmdk into the 2Gb split-sparse format.

This packs almost as good as the "streamoptimized" format used for OVF/OVA

I avoid OVF/OVA when ever possible - I have wasted too much time with manually editing the xml-files or guessing good vmx-files.

Use OVF?

I would use ovf/ova for packaging and distribution still, but for moving vms between lets say a test/dev farm that is isolated and moving it to a production farm, you could use the copy method, or another tool like a backup tool. It really comes down to custom settings in the vmx, the vmdk is the same. This is not to say OVF doesn't work or have it's place, just a word of caution and advice.