If you install and uninstall a lot of packages using apt, aptitude, or dpkg, you may find that you end up with a lot of redundant packages, or ones which have been uninstalled but the config files are left behind.
You can find packages which have been removed but still have config files by running (basically the status field will be ‘rc’):
dpkg -l | grep “^rc”
Or, suppose you installed mysql 5.1 from my previous post using the dotdeb repositories and wanted to see a list of what was installed:
dpkg -l | grep dotdeb
Now, removing those packages is easy, all you need to do is pass the list to dpkg –purge using awk in a similar way to grep above, so the 2 examples above would become:
dpkg --purge `dpkg -l | awk '/^rc/{print $2}'`
dpkg --purge `dpkg -l | awk '/dotdeb/{print $2}'`
(note that you may need to delete and retype the backticks depending on how cut and paste is handled)
Using the methods above, it should be easy to clean up your system.
I finally decided to take the plunge and upgrade a few of my Etch servers to Lenny, and the process was a lot less painful than I was expecting.
These are basically the steps from the official manual, but I cant guarantee that your system will upgrade as easily as mine – as always when upgrading you should backup your data and be prepared for the worst.
Usually I prefer apt-get over aptitude, but the official documentation recommends aptitude to do the upgrade, so heres what you need to do (as root)
First, edit /etc/apt/sources.list and change all mentions of etch to lenny. If you use vim, you can simply do the following:
vim /etc/apt/sources.list
(then, in vim)
:%s/etch/lenny/g
:wq
Then update…
aptitude update
At this point, you might receive the following error (I did on every server I upgraded)
W: There is no public key available for the following key IDs:
4D270D06F42584E6
W: You may want to run apt-get update to correct these problems
To fix this, you need to install the following:
aptitude install debian-archive-keyring
aptitude update
Now you’re ready to do the upgrade. The safest way to do this is in 3 parts
aptitude install aptitude
(updating apt first is a safe way of doing things)
aptitude upgrade
(when this finishes)
aptitude dist-upgrade
When this has finished, your system is upgraded to Lenny! All you need to do now is reboot, and hopefully the system will come back up and be running Lenny.
