Kai Mai's Blog - Take Back the Web - Nodes for linux

How to Check Disk Space and Directory Space in Linux

Thu, 26 Mar 2009 10:21:50 -0700

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

Get Rid of Duplicated Entries/Processes in htop Display

Wed, 18 Feb 2009 23:28:50 -0800

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

Chinese American Food != Food in China but == Linux

Sun, 04 Jan 2009 22:39:17 -0800

Reporter Jennifer 8. Lee talks about Chinese American food which is not really the kind of food you can get in China. She digs deep to find history of common Chinese American dishes like General Tso's chicken, and fortune cookies. She also discusses how 110 people won lottery with the same set of numbers. The most entertaining part is that she compares Chinese American food with Linux(yes. the open source operating system!)

Tags: linux chinese_american_food fortune cookies

Linux/Unix Console Tricks: Multiple Screens within One Console, Tailling Multiple Files with multitail

Tue, 23 Sep 2008 23:46:50 -0700

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

Ubuntu 8 on VirtualBox Hosted on Windows

Thu, 24 Jul 2008 23:57:49 -0700

I recently got a Macbook Pro. But I can no longer use VMWare on Mac to run Linux because VMWare charges for its Fusion player on Mac. Fortunately, I can use VirtualBox which is free for all platforms.

Here are the steps to get Ubuntu 8(Guest) up and running in VirtualBox on Windows(Host):

Download the ISO version of Ubuntu 8
Open VirtualBox. Create a new image. I gave it a 16GB virtual disk.
Attach the Ubuntu ISO image as cd-rom
make sure the boot sequence starts with cd-rom

Tags: linux windows ubuntu vmware virtualbox

LinuxWorld 2005 - Keynotes

Mon, 29 Aug 2005 19:36:58 -0700

In the spirit of "Better later than never", I would blog my San Francisco LinuxWorld trip. It's my first-eve LinuxWorld trip.

Day 1:

I attended the keynote by Charles Phillips from Oracle.
Oracle chose Linux as its part of certified stack because Linux is open, and Oracle does not have its own OS. If Orcale apps have problems with Microsoft OS, it will have to get the support from MS. But with Linux, everything is open. Oracle can troubleshoot problems themselves and determine whehter it's a OS problem and application problem. If Oracle finds any bug, it'll fix it and contribute fixes back to Linux.

Tags: linux linuxworld patent