In the past I always did run ‘Ubuntu Cleaner’ or Synaptic to loose the deb files, old kernels, configs and unneeded packages. According to Ubuntu Cleaner I now have 1296 deb files, 3 old kernels, 2 package configs and 8 unneeded packages.
I think I can delete the 1 GB of deb files. For the others I’m not sure.
I expect, if I want to loose the old kernels, package configs and unneeded packages, I have to destroy the older snapshots.
Are ‘Ubuntu Cleaner’, ‘apt autoremove’, apt clean/autoclean and synaptic still safe to use or might I harm accidentally a snapshot?