# uname -a

Version française.

This is a not-so-concise how-to about setting up an incremental backup, using Backupninja with Duplicity backend on Debian.

Abstract

If you know what a backup is, you should know there are several types of backups :

• A full backup is when you just copy all your files, hoping that the hard drive on the backup server will not explode after 3 backups.
• An incremental backup consist in a base full backup, and the next backups are just "diffs" sent to the backup server, to keep track of modified files.

Obviously, a full backup is easier to read and to restore because it's just plain files, whereas an incremental backup has a specific file format to represent diffs. But considering the gain in speed, bandwidth, and disk space, your choice for a long-term backup solution should be the incremental backup.

The tools

Duplicity is an opensource software similar to rdiff-backup. It creates incremental backups. Duplicity can also encrypt your backups, so they can be safely sent to any remote disk provider. A classic setup for Duplicity would be using rsync as a backend to send files faster to the remote backup server, but you can also use a local drive, a remote FTP server, or an Amazon E3 cloud server. As the title says, I will be using rsync for that setup.

But what about databases ? Databases can't be saved by simply copying files, it could lead to corrupted and unusable data in your backups, so you would use a backup script to fetch your databases before sending it to Duplicity.

Good news : backupninja is the global solution you need. Backupninja is a sort of "backup-master" : it can fetch different type of data (files, databases...) from different sources and sent it to different destinations (plain backup, duplicity, etc). you just have to write a specific config file for each source !

We will use backupninja to fetch our databases, we will add these SQL archives to our files backup, send this to Duplicity backend, and finally send it to our backup server with rsync. And with just 3 config files (one by SQL type, one for Duplicity and rsync).

Let's go !

Every rule has its exceptions, setting drupal_set_title directly on form_alter doesn’t work for node form title. To customize pages like “Add node”, or “Edit node” :

• Make a module

• Add a function to implement hook_form_alter

• Add a form afterbuild in your hook_form_alter implementation: $form['#after_build'][] = '_my_callback_form_set_title'

• In '_my_callback_form_set_title', use drupal_set_title to change the form title: drupal_set_title(...)

• Update system table to have the weight of your module greater than Node module (on a default install, core modules are weighted 0, so set your module weight to 1).

• Rebuild registry, clear caches.