Where is crontab located?

User crontabs are usually in /var/spool/cron/


System jobs are usually in /etc/ under cron.d cron.hourly cron.daily cron.weekly depending on the schedule.

Install htop on CentOS 5.4

The default RPMforge repository does not replace any CentOS base packages. In the past it used to, but those packages are now in a separate repository (rpmforge-extras) which is disabled by default

Read more:
http://wiki.centos.org/AdditionalResources/Repositories/RPMForge

Installing LAMP and Ubuntu

Install LAMP/PhpMyadmin following the instructions in the link bellow:
http://tuxtweaks.com/2010/04/installing-lamp-on-ubuntu-10-04-lucid-lynx/

In the case where the MySQL root has is configured to has NO Password follow instructions bellow to configure PHPMyAdmin accordingly.
http://wiki.oseems.com/web/phpmyadmin/enable-login-without-password

Find Out My Linux Distribution Name and Version

lsb_release Command

The lsb_release command displays certain LSB (Linux Standard Base) and distribution-specific information. Type the following command:

$ lsb_release -a

Sample outputs:

No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 6.0.1 (squeeze)
Release: 6.0.1
Codename: squeeze

Reference
http://www.cyberciti.biz/faq/find-linux-distribution-name-version-number/

rsync backup

Dry run

rsync -a --delete /SOURCE/ /DESTINATION/ --update --progress --stats -n

Run

rsync -a --delete /SOURCE/ /DESTINATION/ --update --progress --stats