10 essential tricks for Linux admins

Posted July 24th, 2008 in Linux/Unix/BSD

Vallard Benincosa posted 10 essential tricks for Linux admins over at IBM's developer works a couple of days ago. This is normally the sort of post I'd just link to in my weekly roundups but there are so many useful things in there I need to be able to locate the post easily so I've created this post for that purpose.

The 10 esstentials tricks are as follows:

1. Unmounting an unresponsive DVD drive. Often you can't eject a CD or DVD because some user's console session is simply sitting in the directory mount point. This tip shows how to kill the process using the fuser command and then safely eject the disk.
2. Getting your screen back when it's hosed. If your screen has got all messed up use the reset command to clear it.
3. Collaboration with screen. "screen" is a utility for sharing a session. This tip looks at how two users can both see the same commands and output being issued which is useful for remote assistance.
4. Getting back the root password. This tips shows what you need to do to reboot and reset the root user's password if you forgot it.
5. SSH back door. This tip shows how to let someone in through a firewall using the port forwarding feature of SSH.
6. Remote VNC session through an SSH tunnel.
7. Checking your bandwidth. This tip lets you measure how much bandwidth you are actually capable of using.
8. Command-line scripting and utilities. There are some useful tips here using looping and so on from the command line shell.
9. Spying on the console. This lets you see what a user is typing, or what output is being displayed, on other virtual terminals.
10. Random system information collection. This has examples of a couple of command line utilities for collecting information about the system.

All useful stuff for both beginners and advanced users. I often forget how to do some things (like how to reset the root password) so articles like this are excellent reference points.