Graphical network simulator GNS3

If you need to test router configuration, prepare a small lab, or just learn something new then download and use GNS3.

How to get rid of slow CentOS mirrors on update

Get rid of slow CentOS mirrors on update.

CentOS/ISPConfig – Easy Postfix upgrade (with MySQL support)

If you are using ISPConfig on CentOS and don’t want to bother with self compiled postfix (because of MySQL support) then use CentOS Plus Repository.

How to exclude package from update on CentOS

Exclude package from an update on CentOS operating system.

Cannot build mysql gem?

If you saw the “Failed to build gem native extension” error while building native mysql gem then you need to install libmysql++-dev package.

Rails migration example

Let’s assume that we want to add friendly_name field to the bookmark_categories table.

How to run specific Rails tests?

Execute specific Rails tests.

Which Ubuntu release are you using?

The easiest way to check Ubuntu release is to use lsb_release command.