debian

I repeatedly ran into the following warnings while trying to update my Debian box using apt-get.

If you've ever worked with Debian or Ubuntu servers, you've very likely had to set up a firewall at some point or the other. However, any changes that are made are not saved and loaded if the server is ever rebooted. The following is a quick guide on how to get this happening:

(root or sudo access is required)

I ran into the following error when I added a new repository to my kubuntu box and ran apt-get update:
E: Dynamic MMap ran out of room. Please increase the size of APT::Cache-Limit. Current value: 123123. (man 5 apt.conf)

To fix this, navigate to /etc/apt/apt.conf.d and edit the file related to debconf which in my case was 70debconf. Add the following line to the bottom of this file and save it:
APT::Cache-Limit "200000000";

Finding all the members of a group is an occasional requirement and while there are a number of ways to do this by parsing the /etc/group and /etc/password files, Debian/Ubuntu come with a simpler solution that performs all this skulduggery for you. This is the members function that can simply be installed using sudo apt-get install members . Once this is done, members of a group named foo can be listed using:
members foo.

Earlier today, I noticed - in htop - that a particular process, let's say 'foo-123', was running even though I had removed the package 'foo' many days earlier. I tried removing it again and found that I was right and that the package had already been removed. The package dependency list was way too long for me to go removing them one by one, or parsing them out and removing the lot.

IRC, however, was very obliging to my query and provided me with the below-pasted nifty solution that did not allow any odd gimmickry:
sudo aptitude search '~i' | grep foo

The Internet will go bust without DNS and the following is a guide to setting up your own DNS server to provide information about your domains and associated services. While this task can be accomplished very easily when using a hosting control panel, it is great fun to set things up on your own.