virtualbox.org

Hi,

some time ago I set up a debian server guest in VirtualBox. This server needs to be backed up every day, so I have to write a backup tool.

Until now I couldn't find a secure way to get a backup. When I copy the whole directory of shutdown guest to an other machine, I will not be able to start the guest there. Beside this it would be important to have no long downtime, so it would be great if there would be a way to backup a running VM.

I found many threads discussing this topic, but I couldn't find any good answer.
Is there any secure and working way to create a backup of a vm which can be started on other machines and don't have to fear that the VM breaks while taking a backup?

Thanks in advance!

Nothing beats a complete backup, and the best way has always been to store the data in a separate partition from the OS which is really the hard part to backup while running. Then you can clone the OS and be able to switch very fast . Then add the data source back to the clone. The data part can be backed up using your favorite hot backup software.
I use rdiff for Linux and you can also use it for Windows but you need to learn how. (google rdiff)

Hi,

thanks for your response!

I found out that the reason for my problems when trying to start a copied vm on a test host were some misconfigurations in this host. Now I can start a copied vm, but i will have to find out how to manage the snapshots.
Is there any way to start snapshots when the whole vm was moved to another host?

If this was possible I think I could just take a snapshot, then copy the whole vm directory and when I need to restore just start the backup from the last snapshot (which should not be corrupted). If this would work there wouldn't be a need for a long downtime.

Snapshots as reliable backups? Big mistake!

OK, i see.

The problem is that i need to keep at least old (already existing) snapshots.

What about following idea:
I keep a copy of actual cm including all snapshots. Then i remove all snapshots from the active vm. Then I write a script which does the following (with vboxmanage) every day: turn off with acpi -> copy vhd to temp location -> start vm -> pack copy of vhd and move to external drive.
Is this a good solution where i don't have to fear any problems when restarting vm or restoring the data from backup?

That would be better, but you still have one part that is delicate. VHD. This type has a header and a footer in the image file and is more likely to become corrupt, especially if the power fails and you have a power pull episode. VDI is the default with VirtualBox and I find it more stable.

Then in your spare time you can figure out how to build a replacement that has the data stored separately and you can use a true backup.

Ok, thanks for your help!