Strange behaviour of linked clones.

[mpack]

This one was reported by a user in the forums here: ​https://forums.virtualbox.org/viewtopic.php?f=6&t=86354&start=15.

I have reproduced the behaviour he reports and must admit that I find it hard to explain.

The behaviour is that, if you create a linked clone then the difference image for the clone is registered in the media register of the base VM, not in the .vbox file of the clone. Surely the media should be registered with the VM which owns the media?

This is not a problem as long as both VMs remain registered. However, if you unregister the clone VM then the media is deleted from the parent VM register. When you try to re-register the clone VM (e.g. you wanted to move it to another drive) you get a media not found error.

It's possible there is some reason for this that escapes me, but frankly it seems like a bug. Of course it would normally escape attention as long as the two VMs remain registered.

[Socratis]

Cc: and +1 from me. The linked snapshot should be definitely be registered with the clone, not with the master.

[JimYang]

+1

as long as Link cloned VM unregistered, it won't be registered again unless you manually edit master VM vbox file and add the harddisk entry back.