I assume this Feature request belongs to debconf, please redirect if
this is not the correct package.
It would be nice if during upgrade, the old configuration were
saved in compressed format, instead of just copying the file
in place.
An example:
.. root root 2566246 Jan 4 18:07 /var/cache/debconf/templates.dat-old
.. root root 2566246 Jan 4 18:08 /var/cache/debconf/templates.dat
For small disks, this becomes imporatant, because the size of all
backup and saved files fill up fast.
If possible, and some dpkg configuration option (permanent in some /etc/... file) to instruct what compression programs to use. Like:
uncompress_command="bzip2 -d"
compress_command="bzip2 -9"