Delete snapshot corrupts Guest

[Lyall Pearce]

Using the VBox GUI on the Linux host, using Fluxbox Window manager.

Click on the VM in question (left panel)

Click the Snapshots Tab (right panel)

I had 2 cold snapshots and one hot one (the latest being a hot snapshot after which I had done an experimental software install)

I went to select the hot snapshot, clicked the wrong one (the newest cold snapshot) and hit the 'delete' button.

I realised my error, but by that time it was too late and in a vain hope to cancel the delete, I clicked the close window button, to no effect.

I resigned myself to having deleted that snapshot - only an inconvenience.

Booted the VM after the snapshot delete had finished and missing files, windows failed to boot. Wrote off the current state and deleted the latest state and reverted to an older cold snapshot.

Rebooted and proceeded to recover.

Whilst it was recovering, I attempted to delete the Oldest snapshot (I was currently running from the second oldest).

That failed with a parameter error. Sorry, didn't take note of the exact code.

Since then, I am not game to go anywhere near snapshots. I use my VM for devlopment, I can't affort to lose it.

I have asked a collegue who also had a snapshot failure to post his details as well, I think he is a bit more upset, however, as I don't think he had the snapshot to go back to, like I did. He, however was running VB on a Windows Host with a Linux guest.

[Lyall Pearce]

VBox Log - not sure if it's the one during the snapshot corruption

[Lyall Pearce]

VBox Log - not sure if it's the one during the snapshot corruption

[Lyall Pearce]

VBox Log - not sure if it's the one during the snapshot corruption

[Lyall Pearce]

VBox Log - not sure if it's the one during the snapshot corruption

[Lyall Pearce]

See Forum topic ​http://forums.virtualbox.org/viewtopic.php?f=7&t=31345

[Klaus Espenlaub]

With the available information there's not much we can do - no error message, no information what the snapshot structure is, no details about what exactly was corrupted.

Since you repaired it somehow the VM config file wouldn't give much hints either.

[Lyall Pearce]

Replying to klaus:

With the available information there's not much we can do - no error message, no information what the snapshot structure is, no details about what exactly was corrupted.

Since you repaired it somehow the VM config file wouldn't give much hints either.

By repair, I simply dropped back to a snapshot prior to the one I was deleting. My confederate had no prior snapshot to revert to, hence he was unable to recover.

[Lyall Pearce]

Just had the problem happen again. I snapshotted, booted, shutdown, revert to latest snapshot, unable to read boot media. Snapshots are broken!

Snapshot directory contents.

 /vms/Machines/Java Developer/Snapshots:
  total used in directory 15456532 available 2992664
  drwxrws--- 2 pearcely vboxusers        104 May 27 12:48 .
  drwxrws--- 4 pearcely vboxusers        123 May 27 12:50 ..
  -rw------- 1 pearcely vboxusers 7481721344 May 24 17:35 {9fde8840-7092-4dc0-9c36-256b2378074f}.vdi
  -rw------- 1 pearcely vboxusers 8345747968 May 27 11:36 {c77105d3-1e20-4d05-b3e9-ece7cf05603a}.vdi

Log and config xmls posted separately.

[Lyall Pearce]

Reverting to latest snapshot is DELETING the EARLIEST snapshot image file, not the LATEST.

The snapshot heirarchy, as I understand it in the above attachments, says to boot from Snapshot {2421443c-ec10-495b-b785-473193e9c4f6}

Snapshot {2421443c-ec10-495b-b785-473193e9c4f6} is using disk image {c77105d3-1e20-4d05-b3e9-ece7cf05603a} (which exists).

Snapshot {2421443c-ec10-495b-b785-473193e9c4f6} is built upon snapshot {59466a85-52ea-414a-bf34-4016b412c9fb} which is using disk image {9fde8840-7092-4dc0-9c36-256b2378074f} (which exists)

Snapshot {59466a85-52ea-414a-bf34-4016b412c9fb} is built upon {e13f04b3-58c2-4408-a819-486670fd7256}, which uses disk image {d5e1198c-7a3b-4b70-8f03-cb62bd5543f4} (WHICH DOES NOT EXIST).

Snapshot {59466a85-52ea-414a-bf34-4016b412c9fb} is the Oldest snapshot, the foundation of the entire snapshot tree.

I am scared of trying a disk compaction - who knows what sort of mess has been made there.

[Gigs]

I have just experienced this as well. It looks like I lost a whole days worth of work. I thought making snapshots was a way to protect my work, in reality it's a dangerous way to lose all your work. I guess the lesson here is that you need to back up your VDI manually and forget about the built in snapshots feature.

I can access my "base" snapshot, but the two differential snapshots are broken. The error given is

VDI: Invalid pre-header

VERR_VD_VDI_INVALID_HEADER

(Can't copy and paste from the window, but this seems to be the relevant parts)

[Lyall Pearce]

This problem has been fixed.

Please close this bug.

[Frank Mehnert]

Thanks for the feedback!