Development for LHC@home

I recently checked the content of the currently used theory vdi (Theory_2019_10_02a.vdi).
I noticed that it's CVMFS cache is split into 2 directories.

dir 1:
cache/cernvm-prod.cern.ch
1416 files
186 MiB

dir 2:
cvmfs-cache/shared
1578 files
247 MiB

Dir 1 contains files that are always in use when the VM starts.
Dir 2 contains files that are used by the running job.
Since the new theory app runs only 1 job and it is very unlikely that this job is from the same type that the one that is already cached, dir 2 seems to be a candidate that could be deleted.

After all data below cvmfs-cache/shared is deleted the following commands must be executed.

Inside an arbitrary directory of the img:
dd if=/dev/zero of=foo.txt bs=1M; sync; rm foo.txt; sync

Outside the VM:
vboxmanage modifymedium --compact Theory_2019_10_02a.vdi


The resulting vdi has only 492 MiB instead of 780 MiB but has no issues running theory.

In Atlas-native cvmfs2 is also shown in top.
David want to make only one CentOS-Linux for both Theory and Atlas.
https://lhcathomedev.cern.ch/lhcathome-dev/forum_thread.php?id=486&postid=6524#6524