virtualbox.org

I've set up my virtual volumes on separate physical drives to reduce the chances of losing both if one host drive fails entirely.

Unfortunately I also require snapshots (in fact, the VM usually runs off a snapshot), and VirtualBox insists on saving the snapshots of all volumes in the Snapshot directory I configure.

Can I somehow tell it that the snapshot of a volume should go to a directory relative to where the volume is located? Or just specify a path explicitly for each volume?

No, VirtualBox has no such feature.

Why not just keep backups on an external drive?

Well that's a shame.

I do keep backups on a separate drive, but backups take a *heck* of a lot more space than snapshots. So I keep a small number of backups with a significant number of snapshots (two snapshots daily, merged automatically every night).

Conceptually, snapshots are taken of the VM, not of individual drives, though of course you and I both know that the underlying drive mechanism could be applied the way you suggest, it just so happens that it isn't (as of v4.1.2).

rstarkov wrote:I do keep backups on a separate drive, but backups take a *heck* of a lot more space than snapshots

On the contrary, a backup written to an external drive takes no space at all on the internal drive. You can't beat that with a snapshot scheme. You don't care about external storage because external storage space is infinite. The only appealing thing about snapshots is that they can be created quickly, plus the GUI provides a nice UI for it, but that isn't enough IMHO to justify the risk. Speaking of risk, I would also note that a snapshot is in no way a substitute for backups, snapshots are way too fragile for that - zap one early "backup" and you lose the lot. True backups don't have that problem. However, the fact that you merge the snapshots after a short interval should at least limit your exposure.

mpack wrote:On the contrary, a backup written to an external drive takes no space at all on the internal drive.

My issue isn't how much space is taken on the internal drive; it's how much space is taken in total. I certainly don't have infinite external storage like you suggest Although since snapshots are taken during the day, the fact that they are quick is also an important factor...

I'll try running without the twice daily snapshots at all, relying just on the nightly backups and the mirroring to two physical host disks that I've set up.

rstarkov wrote:I certainly don't have infinite external storage like you suggest

Sure you do - anybody with a USB port or a DVD-R writer drive potentially has infinite external storage, meaning that your storage space is not limited by the hardware. Hence space taken on external storage is not very important - even if you wanted to keep VM backups forever, the cost of a new USB hdd is probably trivial compared to your time.