Crontab Job

·        List all the cron job

root@hostname]# crontab -l                   

0,5,10,15,20,25,30,35,40,45,50,55 * * * * /root/checksendmail >/dev/null 2>&1

·       Format

Your cron job looks as follows for user jobs:

1 2 3 4 5 /path/to/command arg1 arg2

Or

1 2 3 4 5 /root/backup.sh

Where,

§  1: Minute (0-59)

§  2: Hours (0-23)

§  3: Day (0-31)

§  4: Month (0-12 [12 == December])

§  5: Day of the week(0-7 [7 or 0 == sunday])

§  /path/to/command - Script or command name to schedule

Issues when installing VirtualBox on openSUSE

·         Which kernel are you running?

uname –r

·         Which kernel packages and sources are installed?

rpm –qa | grep kernel

·         Which kernel does the following link point to:

readlink /usr/src/linux

·         Install kernel development code. If the version of kernel you are running is different from the source code you installed, use the following to downgrade the source code:

zipper install --force kernel-devel-3.1.0-1.2.1.noarch       // the red part should be replaced with the version you want to install

·         Sometimes you may also need to install some tools

sudo Zypper install gcc make 



lll

How to find a large file in linux

Reference
http://www.linuxnix.com/2011/02/find-large-files-linux.html

#find /Telecom/ -type f -size +123234k -exec ls -lh {} \;