VBoxManage list <xxx> hangs on Linux (CentOS 5.11)

[chris_r]

When issuing any of the VBoxManage list <XXX> commands, the process never terminates or prints something (it "hangs"). All used to work, but at some point VBoxManage refused to work as before. I unfortunately cannot reproduce the exact commands that have led to this, as I heavily scripted based on VBoxManage. I make use of snapshots (especially restoring them automatically), attaching .ISO files, enabling PCAP tracing and powering off VMs.

Also VBoxManage showvminfo <vmname> does not work anymore: VBoxManage: error: Could not find a registered machine named <xyz>

$ uname -a:
Linux hostname.net 2.6.18-238.12.1.el5PAE #1 SMP Tue May 31 14:02:45 EDT 2011 i686 i686 i386 GNU/Linux

$ cat /etc/redhat-release
CentOS release 5.11 (Final)

$ VBoxManage -v
5.0.10r104061

Find here a complete strace output of VBoxManage list ostypes:

​http://pastebin.com/PDc3PDS8

Find here the complete VirtualBox.xml:

​http://pastebin.com/JXcVbAiY

If you need more input please let me know.

Thanks for your help!

[chris_r]

Actually, a reboot *did* fix this issue. I assumed I rebooted when writing this ticket, but in fact, the reboot did not occur due to a pending VBoxManage list command. When I manually killed this process, the system restarted and all worked fine again.

Still, the problem I faced looks similar to #5961. I will generate a core dump the next time this problem occurs (it already happened trice now).