encrypted unattended backups with anacron and duply

If you are using a laptop as your main computation device having reliable and uptodate backup should be a strong priority. A laptop can be stolen, can fall or as any other computer die in a cloud of smoke (like my last laptop did $^%# ).

For quite sometimes I’ve used duply that is a nice an intuitive frontend to duplicity. Duply allows you to have backups that are : encrypted incremental * offsite

This is basically everything that I want from a backup solution. A nice article about duply here. Since I don’t want to remember to run duply every now and then, I want a daemon to think about it at my place. If you are using a laptop, cron is not your friend as you laptop might be sleeping or simply not connected to the network.

A solution that I knew about for years is anacron. Today I set it up following these instructions. I’ve created 4 different profiles to backup different part of my home directory : home, pictures, media and projects and instructed anacron to run the backup for home and project daily while the rest only weekly.

Since the backup is unattended I’ve used the options of duply that will take care of creating a new full backup each month (2 months for pictures and music). To do this you need to call duply as

duply <profile> backup

and specify the option MAX_FULLBKP_AGE=1M in the conf file of your profile.

I can not sleep better … somebody/something else is looking after my data

And …

something else I might add in the next few days is a script to detect the type of network I’m connected to and to launch the backup accordingly. Some like :

#!/bin/bash

$backuphost=backup.example.org

#gw="$(ip route | awk "/^default via/ {print \$3}")"
#ping -c 1 "$gw" > /dev/null

ping -c 1 "$backuphost" > /dev/null
result="$?"

dev="$(ip route | awk "/^default via/ {print \$5}")"
if [ $dev == "eth0" & $result == 0 ]; then
  # you can run your backup
  echo "wired"
  exit 0
elif [ $dev == "wlan0" & $result == 0 ]; then
  # you can run your backup ... or not
  echo "wireless"
  exit 0
else
  # you should try again another time
  echo "disconnected"
  exit 1
fi