Should snapshot from v5 load in v4?

[DonMorton]

Hello,

I've looked around for the answer to this to no avail.

I've created a Linux guest (on a Linux host) in Virtual Box 5.0.12. I move it to another computer and it fails to load in a VirtualBox v4, but is successful in VirtualBox v5. Is this expected behaviour, or should I be looking elsewhere to understand why it's not loading on the machine that runs VirtualBox v4?

[mpack]

Are you sure you mean snapshot, and not saved state?

Snapshots have not changed format in all the time I've been using VirtualBox. If you move the VM folder properly then you shouldn't have any problem - which is not to say that snapshots are a good idea.

OTOH saved states are designed to making loading faster - they are not designed to be portable. They will certainly not be forwards compatible, i.e. VBox v4 will not be designed to open a v5 saved state, time machines being in short supply at this time.

[DonMorton]

Yes, I meant snapshot, so thank you for confirming that the snapshot formats have been stable across versions.

I'm a bit concerned about your comment suggesting that snapshots may not be a good idea, but I'll start a new thread to ask about that.

[mpack]

All you have to do is Google: "snapshot problem site:forums.virtualbox.org".

[DonMorton]

OK, thank you for this. Very interesting.

What I think I understand from all of this is that a chain of snapshots may not be stable, and that full cloning offers most reliability. That's fine with me. I'm not interested in diffed version control or anything. I just want to be able to create a single snapshot of a given VM and make it available for students to download and run in their VM's. I'll do full clones to back up my evolving images.

[socratis]

I just want to be able to create a single snapshot of a given VM and make it available for students to download and run in their VM's.

A snapshot by itself cannot run. You need the basis of the VM as well. A snapshot is a difference image, i.e. useless on its own.