There is a long guide on how to upgrade CiviCRM for drupal
You should be familiar with all the steps described in the manual, and understand how the particular steps impact/affect your installation. The short version below is known to work with our setup, and with 'routine' upgrades.
Here is the short version:
- backup your database(s)
sudo ~/bin/backup.db.sh drupalsudo ~/bin/backup.db.sh civicrm[1] - download the code
wget https://download.civicrm.org/civicrm-4.6.5-drupal.tar.gz - put site in maintenance mode
drush vset maintenance_mode 1(Make sure you are also logged in as Admin) - move old code, and unpack new code
mv civicrm /tmp/ && tar xvzf civicrm-4.6.5-drupal.tar.gz - run the upgrade script
/civicrm/upgrade?reset=1 - put site in operation mode
drush vset maintenance_mode 0 - toast
Note that in the event that you get errors, you may need to clear the cache:
sudo -u www-data drush cache-clear civicrm
The even shorter version is to use drush civicrm-upgrade --tarfile=./sites/all/modules/contrib/civicrm-5.1.2-drupal.tar.gz --backup-dir=/tmp/ does all the above for you.
