I got the following error when trying to vMotion a VM from one SAN to another.
The VM failed to resume on the destination during early power on.
First I tried looking at ESXi host /var/log/vmkernel.log but in there all I got was
Migration considered a failure by the VMX. It is most likely a timeout, but check the VMX log for the true error.
Because this failure happened so late in the process (around 72%) I realized that it’s probably failing during resume. It turns out that during storage migration the machine gets suspended for a very short period of time and has to start back up (with the new disk attached underneath). Well this made me look at the VM’s own vmware.log … sure enough I found the smoking gun there
[msg.loader.biosfd] Could not open bios.440.rom (No such file or directory).
That’s when I realized that when I set this up long ago, I was forced to use a workaround of including this special bios.440.rom file along with the VM to make it compatible with the OS. Sure enough, so many months later I forgot about it. After I copied the file across to the destination manually, the migration succeeded without a problem.