[Solved] How to share another VB installation

[gcab51]

Hi,
I have VB (v. 4.3.36) running fairly under Debian Jessie.
In a separated directory I have installed the new Debian Stretch 9.4 and installed VB (5.1.3).
Now, I would like not to repeat the installation of the various OS's (WinXP specially) and use the virtual disks of the other installation. Are they compatible between the two VB releases ?
I tried and connect them (presently they are dynamic .vdi), but got WinXP running with just the basic utilities. As far as I could understand from the User Manual I should have them configured as "fixed size". However I am not sure about, and could not find the way and the commands to convert them (if it is possible to do).
Thanks for help

[socratis]

Are they compatible between the two VB releases ?

Yes, they are.

and use the virtual disks of the other installation.

Don't focus just on the VDIs. A VDI is equivalent to the hard drive of a computer, but there are other parts/definitions/recipes in a computer, more than just the HD. What you need to do is to "register" the VM, by going in VirtualBox and selecting "Machine" » "Add..." and select the .vbox file for that VM.

It can be tricky sharing VMs among OSes, but it's doable. One thing you got to watch for is the path bindings and network adapters. But if you've kept the defaults for a VM (i.e. VDI, Snapshots, .vbox and Logs in the same directory) it should be fairly easy. Especially since you're running two versions of the same OS in essence.

[gcab51]

I see, the key point is to add the .vbox file not the single .vdi disks. That solved my problem.
Thank indeed for the prompt and corteous help !

[socratis]

Exactly. The .vbox file is the VM recipe, which includes a pointer to the VDI(s) that need to be loaded.
Glad you got it going. Marking as [Solved].