Device eth0 does not seem to be present, delaying initialization.

You might have come across this headline, especially if you working with Oracle Virtual box machines, machines those are cloned from previous setups etc.


To resolve the issue, just remove the file /etc/udev/rules.d/70-persistent-net.rules and reboot the machine. This file contains the MAC address details associated with the machine. If you don’t want to reboot the machine, run the below command :

udevadm trigger --subsystem-match=net

This command will trigger the rules again.

Enjoy ๐Ÿ™‚


Transfer file to a remote server

rsync -azh path_to_file -e 'ssh -p port_number'


rsync -e 'ssh -p port' -avzr /home/fileย  root@IP:/home/destination


rsync -av --progress --inplace --rsh='ssh -p1777' /tmp/file_name root@IP:/tmp/

from remote to local :

rsync -avz -e "ssh -p port_number" root@IP:/source/ /destination



z : compression; v : Verbose ; r : Recursive;

Note :
There is an important thing while giving the source parameter.
rsync -az source ip:/destination will move the folder source to the destination
rsync -az source/ ip:/destination will move all the contents of the folder source to the destination


Print Calender in Linux

Use the Below command :

cal ‘month’ ‘Year’

Eg : cal 1 2013

will list the January 2013

Eg: cal 2013

will list the calender for 2013


How to use Screen command

To create a new screen session :

screen -S ‘theg’

To save and exit from the screen session :

ctrl + a+ d

To exit from the session :

ctrl + d

To list the screen sessions available :

screen -ls

Login to a screen session available :

screen -r ‘screen_id’


Change/Reset mysql password

You can use the below steps :

1) service mysqld stop
2) mysqld_safe --skip-grant-tables &
3) (hit the enter key)
4) mysql -u root
5) use mysql;
6) update user set password=PASSWORD("MYNEWPASSWORD") where User='root';
7) flush privileges;
8) quit
9) service mysqld restart
10) mysql -u root -p

If you know the old password, use the below command to change the root password :

 mysqladmin -u root -p'oldpassword' password newpassword 

Enjoy ๐Ÿ™‚


Add System Recording in Elastix

Login to the Elastix Server

Select System recordings

Enter the extension number if you are recording from the phone

Dial *77 from the phone corresponding to the extension number

Record the Message

Dial *99 to listen the message, *77 to re-record

Name the recording and Click ‘Save

The new recordings will be available in the location : /var/lib/asterisk/sounds/custom/