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CategoryComputingTips > DebianCompTips

== Debian GNU/Linux Tips ==

=== See all of dpkg -l ===

`dpkg -l` gets cutoff?  Use:

`COLUMNS=200 dpkg -l`

or if you just want package names:

`dpkg --get-selections`

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=== Keeping up with changes in packages ===

`apt-get install apt-listchanges` - I like to keep up-to-date know what's changed on my woody boxes. This emails you the diffs of upgraded packages when you run apt-get upgrade.

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=== Some common apt problems ===

I keep finding out that a number of people don't know these two things.

Firstly, {{{E: Dynamic MMap ran out of room}}} errors when doing an {{{apt-get update}}} are easily resolved by adding a line to /etc/apt/apt.conf like so:

{{{Cache-Limit "8388608";}}}

(There's no special significance to this number AFAIK except that it represents 8MB, and has always been good enough for me. I suggest trying 16777216 if it doesn't work...)

Secondly, running out of space in /var is quite common for newbie debian users. Packages downloaded by {{{apt}}} are stored in {{{/var/cache/apt}}}, so if this gets full you can end up with logging and mail delivery breaking and stuff. The solution is to either have this directory on its own partition, or to use {{{apt-get clean}}} every so often. (Note that tools like {{{dselect}}} apparently do this automatically, though)