Hello Yakito,

First thing you need to do is stoping the server by finding the process use command 

sudo ps -aux | grep openerp-server

then in the output you will have process id after the username.

software  4761  9.2  1.7 131124 69256 pts/10   Sl   11:04   0:04 python openerp-server
software  4776  0.0  0.0   4680   800 pts/10   S+   11:04   0:00 grep --color=auto openerp-server

here 4761 is the Process id and need to kill the process

using this command

sudo kill -9 4761

Now we will see the different way to start server and stoping it in a easy way. Killing processes as above is not good for computer health.

Option 1 :

You can start the OpenERP server without "&" sign.

It will run in terminal and you can see the logs over there.

on pressing of "Ctrl+C", It will stop the server and you can start again the server by just "/opt/odoo/openerp-server" command.

Option 2 :

You can start the odoo server by

cd /opt/odoo/

./odoo.py

or you can start it by

python /opt/odoo/odoo.py

After all this when you want to stop the server, Simply just press "Ctrl+C".

Regards,

Hardik