How to unmount while device is busy

Sometimes You might get the following error messages while unmounting
# umount /dev/sda2/
umount: /dev/sda2:device is busy
Try the below command
# fuser -m /dev/sda2
It will show the process id which is causing it
If you get the process id then you can umount!!!!!!

Fedora:How to restore deleted desktop panel

STEP 1:Make a directory
[antony@localhost ~]$ mkdir bak
STEP 2:Move the following files
[antony@localhost ~]$ mv {.gnome*,.gconf*} bak/
STEP 3:Reboot

Enable root login in GUI Fedora

STEP 1:Open the terminal and edit
vim /etc/pam.d/gdm
Comment the following line #auth required pam_succeed_if.so user != root quiet
STEP 2: Also Edit /etc/pam.d/gdm-password
Comment the following line #auth required pam_succeed_if.so user != root quiet
Done...

Disabling iptables in LINUX

For Fedora,Try the following commands
#service iptables save
# service iptables stop
# chkconfig iptables off
For other Linux distributions
# iptables -F
# iptables -X
# iptables -t nat -F
# iptables -t nat -X
# iptables -t mangle -F
# iptables -t mangle -X
# iptables -P INPUT ACCEPT
# iptables -P OUTPUT ACCEPT