I have a Virtualbox virtual machine that I use on an almost daily basis. When I exit I usually save the state of the machine, but all important data has been saved.
On the same machine I run Backblaze (one of those remote backup solutions), and I recently noticed that it's often trying to backup huge .sav files, thus affecting my network connection.
My understanding is that that file contains the currently saved state of the Virtual Machine. Do I really need to backup it? What would happen if I were to recovery the hard disk state without the .sav file? Wouldn't that just show me the Virtual Machine as it was the last time that I rebooted it?