virtualbox.org

I run vbox 4.3.22 at home. I have a 3TB USB 3.0 external HDD with a partition to store VMs. I sometimes reload windows on the host, and install the newest vbox set the preference for machine storage to a folder on the eternal the VMs are saved in. I would think that if I just o to the external open the vbox VM file it should read the settings and get the VHD that is in the same folder on the eternal. The drive letter for the external is always set to the same value after restore windows. Folders, etc on the external remain the same.

When I use the UI to make a new vm and specify old VHD i get duplicate file error. If use external to try and open the VM and import it I'm seeing similar errors. Most the folders on the external have a vmfile and a VHD, and maybe a couple snapshots, or images for the VM image.

Google says can change uuid from the vbox CLI. I think some places run vbox for servers, it seems they would put the VM drives on a NAS, File server, SAN. Then you can cluster VMs like VMware, Hyper-V. If a host goes down the VMs stay on on anther server Fix issue you point Vbox back to the network storage. Start the VMs aain and your running. I can't imagine using CLI to change the UUID for a bunch of VMs in a case like this. Yes vbox may not be best for that setup for that, but seems allot of people would use it like I am.

Not sure this is simple fix, could use import or export tool, or something else.

You can't register the same VM twice, that's why you get the error message. You've told VBox where the VM is, so fine you don't need to tell it again. If all you do is unplug the external drive and later plug it back in again, then the VMs on it are still registered from last time, provided the drive letter didn't change.

Running VMs from external storage is not recommended btw. Catastrophic data corruption is just a matter of time, unless you are extremely disciplined about always flushing the drive before removing it, and of course never removing the drive while a VM is running.