utility

Surprisingly, I often run into the problem of running out of disk space in Linux.

Here are some simple commands to check what consumes the most space:

• "df -k" shows the percentage of disk consumption for each partition
• "du --max-depth 1 -h /" shows how much space each directory under "/" consumes in megabytes
• "du -sm * | sort -n" does the same thing as the previous command

stackoverflow has a good discussion as well.

Tags: linux utility disk

htop is a "top" on steroid Linux utility for interactively viewing processes.

What puzzled me was that some of the process counts seem to be doubled.

I know for a fact that I run two Thin servers(BTW, Thin seems to use less memory than Mongrel). But htop shows 4 processes

3895 root      20   0  187M 95484  3732 S  0.0  9.1  0:55.42 thin server (/tmp/site.1.sock)                                                                               
3899 root      20   0  187M 95484  3732 S  0.0  9.1  0:03.26 thin server (/tmp/site.1.sock)

Tags: linux utility htop

I find the following Linux/Unix console tricks really handy:

Multiple screens within one console

You need to SSH into a Linux server and work with multiple screens(eg: tailing a log, vi a source file, etc). Instead of opening multiple SSH sessions(multiple putty in Windows, or terminal windows in Mac), you can open multiple screens within one console window by using "screen" command.

yum install screen
screen

Here are the shortcuts:

• ctrl+a + ctrl+c to add a new screens
• ctrl+a + ctrl+a to switch between screens
• ctrl+a + " to see a list of screens
• ctrl+a + (a number) to switch to the "numbered" screen

Tags: linux console utility screen trick logging shell command