Last Updated on September 5, 2021 by Christopher G Mendla
I was in the middle of juggling a dozen things. After rebooting my Windows machine my VM would not start. I found a work around that restored my VM
Overview
I run Oracle Virtualbox on my Windows machine to run Ubuntu for a Ruby on Rails development environment. I back up the virtual machine periodically.
I was in the middle of a bunch of chaos. I had my VM running and restarted Windows before shutting down the VM
The Virtual Machine would not start.
After rebooting Windows, I tried to start the virtual machine. I got a nasty error basically saying “Hey dummy, you broke the VM”. Of course, it didn’t REALLY say that but that would have summed things up. It showed a ‘recovering you VM error’
The restore would run it’s course and then show an error indicating that the restore failed. The error was titled “Failed to open a session for the virtual machine”
Well that certainly ruined my day. I defied logic and tried the same thing a couple of times getting the same failure.
The text of the failure was as follows:
virtio-scsi#0: Bad count of I/O transactions to re-do in saved state (0xddff, max 0x400 - 1) [ver=1 pass=final] (VERR_SSM_DATA_UNIT_FORMAT_CHANGED).
Result Code:
E_FAIL (0x80004005)
Component:
ConsoleWrap
Interface:
IConsole {872da645-4a9b-1727-bee2-5585105b9eed}
That certainly looked serious and intimidating. I was thinking I might have to ‘break in’ to the virtual machine but wasn’t sure where to start.
Try the easy fix first
I never ran into this particular problem before. Logic told me that there might be a tool in Oracle Virtualbox to fix this.
Backup, Clone, Duplicate BEFORE trying to fix the problem.
Before I went any further, I cloned the virtual machine. That took about 10 minutes with my system and configuration. That way, I could try to recover the VM but would have a backup in case anything went wrong.
WARNING – WARNING – WARNING – be SURE you back up the virtual machine before trying to fix it. Even if you have a recent backup, there will be changes that are not in that backup.
“Discard Saved State” saves the day
After looking through the Oracle Virtualbox menus and doing some research, I found an option that looked promising. It was a menu item to “Discard the saved state”.
When I tried this option, if I recall correctly, I got some warnings. I knew I had a solid backup so I accepted the warnings.
Results: Success
After running ‘Discard Saved State’ I was able to successfully restart my VM. I was never so happy to see that big Ubuntu cat with the laser eye stare.
This worked for me with this particular error and the current state of Virtualbox, my VM and my host machine. This might not work in other cases (That is why we clone before trying to fix the VM)