linux command change files extension jpeg to jpg

rename 's/\.jpeg/.jpg/i' ./*

Disable ssh root direct login

in /etc/ssh/sshd_config

/PermitRootLogin yes

change to 

/PermitRootLogin no

then

/etc/init.d/ssh restart

linux check if two files are identical

linux check if two files are identical

use md5sum to check if their hash are identical

debian, linux, what is my current I/O scheduler?

debian, linux, what is my current I/O scheduler?

cat /sys/block/sda/queue/scheduler
cat /sys/block/sdb/queue/scheduler

difference between ubuntu server and ubuntu desktop

what is the difference between Ubuntu server and Ubuntu desktop?

Kernel Differences:

• The Server Edition uses the Deadline I/O scheduler instead of the CFQ scheduler used by the Desktop Edition.
• Preemption is turned off in the Server Edition.
• The timer interrupt is 100 Hz in the Server Edition and 250 Hz in the Desktop Edition.

convert ubuntu 10.04 desktop edition to ubuntu 10.04 server edition

convert ubuntu 10.04 desktop edition to ubuntu 10.04 server edition

sudo apt-get update
sudo apt-get install linux-headers-server linux-image-server linux-server

debian apt-get install trac 0.12

do this

sudo apt-get install trac

at this point you will install only  trac 0.11

then download Trac-0.12.3.tar.gz

tar -xpzvvf Trac-0.12.3.tar.gz

cd Trac-0.12.3

sudo easy_install Genshi

sudo python ./setup.py install

then finally a successful build of trac 0.12 on debian 5.0/6.0