Recipe 3.12. Maintaining the Debian Package Cache

3.12.1 Problem

You want to keep your package cache and package lists tidy and up-to-date, so that apt will work correctly and not encounter bogus dependency problems.

3.12.2 Solution

Use apt and dpkg.

Remember to run apt-get update after making changes to /etc/apt/sources.list, and run it periodically to keep package lists current.

To look for downloaded, uninstalled packages, use:

$ dpkg —yet-to-unpack

To check for broken dependencies, use:

# apt-get check

To remove cached packages that are no longer needed, use:

# apt-cache autoclean

To remove all cached packages, use:

# apt-cache clean

To show partially installed packages, use:

$ dpkg —audit

If dpkg —audit returns any results, as in the following case:

$ dpkg —audit

vpw   (no information available)

first check that the returned package exists:

$ dpkg -l vpw

Package `vpw' is not installed and no info is available.

If it exists, either complete the installation or remove it. If it is not installed, search both /var/lib/dpkg/available and /var/lib/dpkg/status for the offending entry, and remove it.

3.12.3 Discussion

Your package cache can easily consume tens, or even hundreds, of megabytes. See for yourself in /var/cache/apt/archives. To conserve storage space, set up a local package cache for your network (Recipe Recipe 3.14).

3.12.4 See Also

• dpkg(8), apt-cache(8), apt-get(8)

• Local documentation (/usr/share/doc/Debian/apt-howto)

• The Debian Reference Manual (http://qref.sourceforge.net/)