On ubuntu, the .deb files in /var/cache/apt/archives after running apt upgrade is kept for around 30 days. On lubuntu, by default, these deb files are deleted upon installation of them.
Now I have a cluster of servers all running lubuntu, I want only the “head node” connected to the internet, and use apt-cache-ng to serve upgrade deb files to the rest. How to let the head node keep the deb files after itself has upgraded?
Excuse me I have no clue after checking apt documents, seems autoclean is already disabled.
This is certainly an apt.conf issue, though you should dig through both /etc/apt/apt.conf.d/* as well as /etc/apt/apt.conf itself.
I think this is what you want (NOTE: from man apt.conf):
Clean-Installed
Defaults to on. When turned on the autoclean feature will remove any packages which
can no longer be downloaded from the cache. If turned off then packages that are
locally installed are also excluded from cleaning - but note that APT provides no
direct means to reinstall them.
man apt-get seems to agree:
autoclean (and the auto-clean alias since 1.1)
Like clean, autoclean clears out the local repository of retrieved package files. The
difference is that it only removes package files that can no longer be downloaded, and
are largely useless. This allows a cache to be maintained over a long period without
it growing out of control. The configuration option APT::Clean-Installed will prevent
installed packages from being erased if it is set to off
Also from man apt.conf:
/usr/share/doc/apt/examples/configure-index.gz is a configuration file showing example values for all possible options.