How to deregister a VM

[jcdole]

Hello.
Sometimes I need to repair a linux vm using a vm running a linux live-cd.
To do so
1 - I make a copy of the defective vm in a temporary folders
2 - I rename the vm folder in '/home/user/Virtualbox Vms'
3 - I add the vdi of the defective linux vm ( which is the temporary folder) in the config of the live-cd.
Then I start the live-cd.

or I use a vm running an install cd ( iso file ) and add the vdi of the defective linux vm.
At the very beginning of the install i choose to run the rescue cd.

Yesterday, I was facing an error : 'Cannot register because UUID Already registered for the file /path/to/vdi/file.vdi' , (or something like that).

The error persisted even after the virtual machine was removed, and the folder containing the vdi file removed..

How to de-register a VM but leaving everything in place.

[scottgus1]

How to de-register a VM but leaving everything in place.

Right-click the VM in the list, click Remove, then Remove Only. (Don't click "Delete all files", it does what it says: it's a one-way no-undo hole to destruction.)

Sometimes I need to repair a linux vm using a vm running a linux live-cd.
To do so...

Why not just boot the existing VM with the LiveCD? Making a copy of an existing drive file prevents attaching that copy back into Virtualbox, because of duplicate UUIDs, which explains this:

'Cannot register because UUID Already registered for the file /path/to/vdi/file.vdi' , (or something like that).

Your process might have worked before, because the process involved successfully unregistering the VM or at least the disk file. You can make a copy of a disk file, but you can't have both the copy and the original registered at the same time.

But the process may be too complicated. The existing VM will boot from the LiveCD just fine.

[jcdole]

Thank you for your answer.
What hapens if I rename the VM folders from /home/user/VirtualBox VMs/SOME_VM to /home/user/VirtualBox VMs/SOME_VM_KEEP.
Normally one get an error of kind "Machine not accessible"
In this case, virtualbox should not find the vdi file described in /home/user/VirtualBox VMs/SOME_VM/SOME_VM.vbox and therefore the vdi file should be usable again?
Isn't it