LHC@home

How can I fix this?

Command:
VBoxManage -q closemedium "/var/lib/boinc-client/projects/lhcathome.cern.ch_lhcathome/CMS_2022_09_07_prod.vdi"
Output:
VBoxManage: error: Cannot close medium '/var/lib/boinc-client/projects/lhcathome.cern.ch_lhcathome/CMS_2022_09_07_prod.vdi' because it has 2 child media
VBoxManage: error: Details: code VBOX_E_OBJECT_IN_USE (0x80bb000c), component MediumWrap, interface IMedium, callee nsISupports
VBoxManage: error: Context: "Close()" at line 1878 of file VBoxManageDisk.cpp

I tiried to run the command manually and with sudo but they kept comming up, I try to rebot and see what happens.

This is a result of a race condition and needs to be cleaned manually.
See:
https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=5982&postid=47976

When I open the VirtualBox GUI theren is no media, since it doesn't run under my account it runs under the boinc account.

I cannot su into boinc as there is no real account for boinc.

I did rm * on all the stuff in .config/VirtualBox, now its back after aborting all the tasks and rebooting.

Guess it was on this box:
https://lhcathome.cern.ch/lhcathome/show_host_detail.php?hostid=9930008

You hopefully removed only ".../boinc/.config/VirtualBox/*" instead of ".../any_other_user/.config/VirtualBox/*".

A bit less rough would have been to:
1. Pause all VM tasks that are not yet started
2. Wait until all running VM tasks are finished
3. Stop BOINC and VirtualBox
4. Edit ".../boinc/.config/VirtualBox/VirtualBox.xml"; Remove all lines between "<MediaRegistry>" and "</MediaRegistry>".
5. Restart VirtualBox and BOINC
6. Resume 1 VM task from each project/subproject
7. After a few seconds resume more VM task (avoid to start too many of them concurrently)

Yes was that host.

On linux the home dir for the boinc user is /var/lib/boinc-client/ so in here.

If it messes up again I can give that ago,

i think that the reason to abort them all was when I tried to run the virtualbox gui as the boinc user, there there a crash report message for Virtualbox something to do with qt.

_usr_lib_virtualbox_VirtualBox.128.crash

After this nothing would run so I just quit them all and rebooted.