March 1, 2006 Linux Sysadmin tools
An interactive process viewer: htop
htop. Most Linux users, when they first wanted to find out what was eating all their CPU time, were taught about top. Top tells you what processes are running and how many resources they’re using … in just about the most unfriendly way possible.
Htop does exactly the same thing as top, but is much less likely to induce migraines. It’s color-coded, which makes it easier to read. It has an easy-to-read summary of CPU, memory, and swap usage displayed as simple bars at the top of the screen. Most usefully, it has the most important keyboard commands permanently listed at the bottom of the screen for easy reference. It also displays the complete command line for running processes, not just the process name.
The nano editor
Despite having used Linux for more than four years, I Know how to use vi or Emacs, but try out GNU nano.
EasyTAGis a brilliant little application for managing the metadata that describes a file’s song title, artist, album, and so forth — for MP3, FLAC, Ogg Vorbis, and other digital media files. You can quickly and easily apply any given tag to any number of files, but that’s just the start. EasyTAG’s best features are its smart features. One simple feature is a little button that numbers tracks in a directory in order from 01 upwards. On the more complex side of things, EasyTAG can rename files based on tags, or fill in tags based on file names, through a simple, variable-based filtering module which has built-in templates that cover many common types of filenames.
How often have you run out of disk space on a partition and wondered what was eating it all, then been frustrated while trying to come up with a console command that would tell you quickly and easily? Filelight is one of the few GUI applications that covers a sysadmin task better than a CLI command.
Filelight gives you a graphical display of your filesystem as a series of concentric segmented rings organized by disk space used. It starts off with an overview of the entire filesystem, with directories that use more space showing up as larger chunks of pie. The directory layers are arranged outwards in concentric circles. You can easily zoom in at any level by clicking, making it a few seconds’ work to identify the culprit in even the largest filesystem. Baobab is a similar utility.
Fanout is a simple utility that does a simple but useful thing: it connects to any number of machines via SSH and executes the same command on all of them. It’s as simple as
fanout "machine1 machine2 machine3" "command".
GNOME Password Manager (GPass)
GPass is not strictly a sysadmin utility, but it’s an essential tool for any security-minded Internet user.
GPass is a password management application that stores unlimited username and password combinations in a securely encrypted database which is protected by a single password or passphrase.
By restricting access to the database file (you can even store it on a USB key and keep it with you at all times), you can get all the security benefits of multiple strong passwords with none of the inconvenience of trying to remember them.
Urpmi’s parallel mode
Urpmi is Mandriva’s package management tool, and it has all the normal features of tools like Debian’s apt-get. It has its own special party trick too. Though using it is a bit more complicated than the other tools on my list, it’s worth the investment.
On a master machine you can define a group of slave machines in a configuration file, and then you can use the
--parallel parameter to perform any Urpmi operation on all the machines in the group. Any packages that need to be installed will not be retrieved separately on each machine, but retrieved just once on the master machine and then distributed to the slave machines prior to installation.