After few months or years later, you will notice unnecessary files, libraries and/or documentation eating up your disk space On Debian or Ubuntu Linux. Try the following tips to free up disk space.

Remove cached .deb files

When you run apt-get command, it downloads and caches the package in /var/cache/apt/archives directory. cd into this directory:
# cd /var/cache/apt/archives
# du –ch
Output:

8.0K    ./partial
838M    .
838M    total

Remove all cached *.deb files using the following rm command:
# rm –f *.deb

Remove Orphaned package

The deborphan command finds packages that have no packages depending on them. The default operation is to search only within the libs and oldlibs sections to hunt down unused libraries. The following command displays orphaned package list:
$ deborphan -sz
Where,

• -s: Show the sections the packages are in.
• -z: Show the installed size of the packages found.

You can remove orphaned package with apt-get command remove option:
# apt-get remove packagename
Alternatively, remove all orphaned package in a single command, type:
# apt-get remove $(deborphan)
Better try:
# apt-get remove --purge $(deborphan)

If you find command line hard to use try orphaner command which is nothing but a neat frontend for deborphan displaying a list of orphaned packages with dialog or whiptail. Packages may be selected for removal with apt-get which is then called to do the work. After removal a new list of orphaned packages is gathered from deborphan. The program ends when either “Cancel” is pressed or no package is marked for removal.
# orphaner

(Fig 01: orphaner command in action )

However some packages are important and if you want to keep them forever, use editkeep command which is a frontend for deborphan displaying a list of orphaned packages (-a for all-sections is implied) and packages which are tagged to never been shown using dialog or whiptail:
# editkeep

cruft command

cruft is a program that goes over the Debian packaging system’s database, and compares the contents of that with the files actually on your system, and produces a summary of the differences. For example, you can clean spool with following command:
# cruft –k

Read the cruft man page for advance usage.

Remove log files

Backup log files and remove them from /var/log directory. To truncate log file you can run for loop:
# cd /var/log/squid
# for i in *; do >$i; done

Also, consider rotating log files using logroate facility.

See also:

• Linux: Debian package management cheat sheet
• How do I rotate log files?
• Read the man pages for: editkeep(1),cruft(1),deborphan(8),apt-get(8) commands.