virtualbox.org

Hi,

Reading about Snapshots at http://www.virtualbox.org/manual/ch01.html#snapshots I understand that a Snapshot is not a backup of existing data. Instead, it marks the beginning of a new storage location where all new data and changes will be written to. If this is correct, I wonder what would happen if a snapshot is done while the VM uses an empty 20 GB fixed virtual hard drive. Doesn't this mean 20 GB of disk space will continue to be wasted as new data is written to the Snapshot?

Thanks.

that's correct.

Ok. Many thanks for the prompt answer!

Happily the issue never arises because nobody in their right mind uses either fixed disks or snapshots anyway!

mpack wrote:Happily the issue never arises because nobody in their right mind uses either fixed disks or snapshots anyway!

I beg to differ about the snapshots. At least one snapshot anyway. Whenever there are major updates such as a new Kernel it's nice to preserve the working machine before updating because many times the updates will break the install. It's much easier and quicker than cloning. I learned the hard way.

You can easily back up a VM without involving snapshots. Cloning speed isn't really relevant IMHO, since you ought to be making proper backups anyway before any major change.

Yes, you could make backups. However in my case where I could have 20-30 VMs at a time, snapshots seem to be quicker and easier and take up less disk space. different strokes etc.

Yes, we could get into the old snapshots vs cloning debate, but here is not the place for it - the OP didn't ask about that. So lets call it quits.

okie doke.

Though perhaps you might try explaining to this chap, why you think snapshots are better than clones.

mpack wrote:Though perhaps you might try explaining to this chap, why you think snapshots are better than clones.

thought we were done? as I mentioned, using ONE snapshot works for me. multiple snapshots can quickly turn into a nightmare.

We were done, but then this prime example presented itself. He only had one snapshot too: not that that helps if you lose the base VDI as he did.

mpack wrote:We were done, but then this prime example presented itself. He only had one snapshot too: not that that helps if you lose the base VDI as he did.

So I guess what you are saying is if someone uses a snaphot/snapshots incorrectly they will have problems.

No, I'm saying that if you damage any file in a snapshot chain then you'll have problems, particularly if its the base VDI. File damage can happen for a number of reasons, not all of them involving improper manipulation of the snapshot files. With a backup there can be no such problem - you just restore the affected file.

mpack wrote:No, I'm saying that if you damage any file in a snapshot chain then you'll have problems, particularly if its the base VDI. File damage can happen for a number of reasons, not all of them involving improper manipulation of the snapshot files.

From what I read he never copied the VDI in the first place. Had he copied the entire VirtualBox folder he would of been fine. It doesn't seem to me snapshots were the problem. It's just all he had left. Had he cloned the VM and managed not to copy that to his new drive he would be no better off.