You can make a backup of your entire instance by using Gandi's Snapshot feature.
From the control panel of your instance, click on the “Activate” link that you see next to Snapshots at the upper-right hand corner of the page:
Configuration includes 4 images, keeped for distinct durations :
Version daily and weekly may overlap depending on the day.
To restore your instance from a Snapshot, start by logging into your instance using sFTP.
Once you're at the root of your instance's disk, browse to the “Snapshot” directory.
The snapshot's directory will look like:
The number that you see before each directory is the unix timestamp. The most recent snapshot is the one with the highest number.
In order to restore data, you will have to copy files to local from the source folder, and then upload them to the target diretory (unless your SFTP software allows you to copy/paste directly trough interface).