Upgrade from 2.8.1 to 2.9 using cli


We want to upgrade from 2.8.1 to 2.9.

If I follow the instructions from this link http://www.freepbx.org/support/documentation/installation/upgrading-your-system :

cd /usr/src/
wget http://mirror.freepbx.org/freepbx-2.9.0.tar.gz
tar zxvf freepbx-2.9.0.tar.gz
cd freepbx-2.9.0
./start_asterisk start # for upgrades use: amportal start

, will our data [extensions, trunks etc] be preserved?

thanks in advance.