Failed to open a session for virtual machine!

[abcuser]

Hi,
I have run a virtual machine but got error "Failed to open a session for virtual machine!". I have checked the Logs directory but it is empty (I have deleted all log files before starting virtual machine), so no new logs get created.

What has happened with my virtual machine? Any idea how to solve the problem? It looks like VDI file got corrupted?
Thanks

My system
Host: Windows XP sp3
Guest: Ubuntu 10.10
VBox: VirtualBox 3.2.10

[Perryg]

Hard to say what happened.
If you do not have snapshots you can try to create a new VM and attach the VDI file instead of create a new HDD and see if it picks it up and works.
(note) you will need to release the old VM and either delete it (not not select delete the file) or name the new VM differently the the other one.

[abcuser]

Perryg, I have multiple snapshots, so I can't just create new virtual machine (or am I wrong). What happened is: I have shutdown guest and guest was exiting. But then VirtualBox hang at the end of shutdown. I have left at least 20 minutes to wait to shutdown (normally it shutdowns in less then 5 minutes) and there was 0% CPU consumption. Then I have rebooted host. After host reboot, I started VirtualBox GUI and started guest but it produced this error. It looks like VBox hang in the end of the shutdown process and if I understand correctly VDI file got corrupted. If I am correct, is there any way I could run some utility to check for errors in VDI and repair them?

[Perryg]

You might want to get in touch with mpack. I don't do snapshots, but if there is any way to get anything back he will know.

[abcuser]

Perryg, thanks for help. I have solved the problem or should I say it has solved it by itself. Yesterday I have hibernated Windows host and today I have resumed it. Just to get error message I have started VirtualBox and run a guest, but what I have seen it just started up without any problem at all. Strange, but it is working now. Is there some kind of self repairing of VDI included in VirtualBox?

[mpack]

Is there some kind of self repairing of VDI included in VirtualBox?

I very much doubt that. More likely is that there is some part of the host VBoxSVC or associated drivers, which does not like to be hibernated. In which case a reboot of the host was all that was needed.

You might want to give some thought to the wisdom of using snapshots. You got away with it - this time.

[abcuser]

You might want to give some thought to the wisdom of using snapshots. You got away with it - this time.

mpack, you are right. Using snapshots instead of real backups is very dangerous. Something goes wrong with main VDI or one of the snapshot and you are out of luck.

Now I did the following:
1. deleted all snapshot from my virtual machine
2. download the latest CloneVDI v2.03
3. cloned VDI file
4. got another wisdom about how to stop making shortcuts to backups