Overwrote a VMDK with the cp command.

[mrme01]

Pretty much as the title says, I have tried using the vmfs-tools package on a USB bootable Ubuntu install, but the version of VMFS is too high for it to mount the partition. I currently have it passed through to my Windows VM, and trying VMFS recovery, but that doesn't seem to find the VMDK.

Any other methods I can try before trying to work out what I have lost?

I think the VMDK was around 1.4TB, but not full, as datastore I was trying to move it to has less than a terabyte free. The file I overwrote it with (same name) was a few kilobytes. I thought it was the pointer file for the VMDK, not the actual VMDK itself. I should have checked the extension.

[continuum]

Do you remember wether you overwrote the name.vmdk or also the name-flat.vmdk ?

If you still have a *-flat.vmdk with the expected size no serious harm is done.
vmfs-tools from Ubuntu using standard repositories will fail with vmdks larger than 256gb.
Can you use vmfs-fuse to list the files ?
Can you use Ubuntu to do this ? (I assume the Ubuntu sees the VMFS-volume as /dev/sdX1 - change this to your needs )
dd if=/dev/sdX1 of=/somewhere/vmfs.1536 bs=1M count=1536
Then I can check if there is a way to create a dd command to extract the vmdk even if the VMFS-metadata may be dead or partially corrupt.
If that does not help it is still maybe possible to extract the vmdk when it was thick provisioned