Auto Update Backup
The goal here is to get a network connected Raspberry Pi to periodically update and backup itself up to an external device or network share.
This is heavily based on the developments presented here 
Copy the script to the home folder on your Raspberry Pi using wget.
cd ~ wget https://raw.github.com/martinrgmiller/RPiAutoBackup/master/AutoUpdateBackup
Create a Backup Location
This location must not be physically on the Pi's SD card, it should be an external USB drive or other share on your network.
The script supports temporary and direct mounting of a network share. Alternatively you can auto mount the shares. Accessing Network Shares.
The method fo authentication for the CIFS shares is a credentials file. This file must be accessable and populated an example of a typical cred file can be found Accessing_Network_Shares#User_Specific_Actions
You must make sure that the location for the backup file is mounted and writeable.
Setup the script
The header of the script header documents the user defined parameters
# EXTDIR must be external i.e. not on the SD card for example a usb stick or network share # BACKUPDIR is the location to write the backup on EXTDIR # PURGE determines if old backups are deleted before zipping the latest sucessful backup, PURGE=false # CIFSHOST is the optional network share host name or address, comment out to disable mounting a CIFSSHARE # CIFSSHARE is the share on the CIFSHOST, required if CIFSHOST is enabled # CIFSCRED is the local path to the CIFS credentials, required if CIFSHOST is enabled # CIFSUID is the users who has write permissions to CIFSSHARE, required if CIFSHOST is enabled
Edit these as required
EXTDIR=/media/cifstemp/Public BACKUPDIR=$EXTDIR/RPi_autobuild_backup PURGE=false CIFSHOST=//192.168.0.8 CIFSSHARE=Public CIFSCRED=/home/raspberrypi/cifs.cred CIFSUID=raspberrypi
External HDD example
Manually mount your USB drive first.
sudo mkdir /media/usbdrive sudo mount /dev/sda1 /media/usbdrive
Edit the script settings to match
EXTDIR=/media/usbdrive BACKUPDIR=$EXTDIR/RPi_autobuild_backup PURGE=true #CIFSHOST=//192.168.0.8 CIFSSHARE=Public CIFSCRED=/home/raspberrypi/cifs.cred CIFSUID=raspberrypi
Here, CIFS mounting is disabled and PURGE has optionally been set to true to delete old backup off the usb drive due to capacity limitations.
Test the Script
$sudo sh AutoUpdateBackup
Move the script to a better location
Assuming you've resolved all the permissions and the scripts runs, copy the script to cron.daily.
sudo cp /home/jack/AutoUpdateBackup.sh /etc/cron.daily/AutoUpdateBackup
Modify the permissions of the script to make it executable
sudo chmod +x /etc/cron.daily/AutoUpdateBackup
The script will now run once per day. Note if you change the file name don't add an extension because script filenames in cron.daily/, cron.hourly/, etc., should not contain dot(.), otherwise
run-parts will skip them.
Note. as of 2013.06.09 for some reason the script doesn't work in cron
To redirect the output the the script to a logfile uncomment the following line in the script header
#exec &> /var/log/AutoUpdateBackup.log
to have the log rotate modify
/etc/logrotate.d/rsyslog and add the following entry after