VBoxManage list runningvms does not list a running VM

[Mark Lewis]

Ubuntu version 13.04, VirtualBox 4.2.10-dfsg-0ubuntu2.1

I have a script that runs "VBoxManage list runningvms" every 5 seconds. A few times per day, often in the middle of the night when there is no activity on my workstation, running "VBoxManage list runningvms" will suddenly return no VMs.

Once it gets into this state, it seems to have permanently forgotten about all of the VMs that had been running. They are still running; I can ssh in and run applications on the VM, and I see the VBoxHeadless processes running, but VBoxManage list runningvms does not return them anymore. If I create new VMs, the new VMs appear in "VBoxManage list runningvms" for a while, but after enough time they will disappear too.

For example, on my host, the current output of "VBoxManage list runningvms" (which shows one VM, allocated since the last event) is:

$ VBoxManage list runningvms
"7b7d9958-677b-4fcf-80fb-a012e5d90f50" {7b7d9958-677b-4fcf-80fb-a012e5d90f50}

But I can ssh into each of my VMs and see the VBoxHeadless processes running for all three of my running VMs:

$ ps -f $(pgrep VBoxHeadless)
UID PID PPID C STIME TTY STAT TIME CMD
tester 1011 506 12 14:16 ? Sl 19:47 /usr/lib/virtualbox/VBoxHeadless --comment 7b7d9958-677b-4fcf-80fb-a012e5d90f50 --startvm 7b7d9958-677b-4fcf-80fb-a012e5d90f50 --vrde config
tester 4854 4710 53 14:10 ? Sl 85:54 /usr/lib/virtualbox/VBoxHeadless --comment 7a7a7f1b-7dcc-47a8-8940-38cda2227498 --startvm 7a7a7f1b-7dcc-47a8-8940-38cda2227498 --vrde config
tester 26982 4710 12 14:15 ? Sl 19:13 /usr/lib/virtualbox/VBoxHeadless --comment 97c14df6-f147-426a-96ce-22ddbb3699ac --startvm 97c14df6-f147-426a-96ce-22ddbb3699ac --vrde config

This doesn't seem to be just a problem with the "list runningvms" subcommand, I can also execute "VBoxManage unregistervm UUID-OF-VM" and the VM will be unregistered; normally that would throw an error if the VM is running.

This is on 13.04.