Ive run vbox for a while now, currently 4.1.16 on Ubuntu 12.4. I use vbox manage to autostart and safely shut down VMs. I have a number of VMs doing various tasks, from print servers to web servers.
All good, all works fine.
Ive recently built a new web server, similar to my other ones, nothing fancy, LAMP and some PHP.
This particular VM keeps failing to respond to anything, that is no communication from the outside, no RDP or VirtualBox Manager GUI access. All I get is a black motionless RDP screen.
I finally I tracked down this is when the VM goes through a poweroff, or a host machine reboot (as handled by vbox tool).
I understand a poweroff to be just that, and I would think there might be a risk of ccorruption just as with a physical machine. But the machine should still boot. And why would this one machine fail to recover 100% of the time, yet all my others have never failed this way?
The only apparent recovery is to go to the last snapshot, which was a session save. All comes back good. But of course for a web server this is catastrophic, because it means if I ever suffer a power failure I am 100% guaranteed to loose all updates to disk since the last session save.
So this cant be right, can it? What is happening here, and how can I recity it and prevent it from happening again. Although I may have some understanding to gain here, there must also be something odd for this to happen to just one of my many (similar) VMs.
Thus far I have created a new VM and moved the vdi to it, but to no avail - same issue.
Can anyone give me any suggestions and or edication that might help please?