jpl & others
I ran into issues with the size of removable backup disks (120Gb IDE on a workstation) and the resultant backup data size (120Gb of data compressing to approx 50Gb).
I was able to get one full backup onto a disk, and a weeks worth of daily incrementals, but the next weekly full backup failed, due to the need to save the new backup in the tmp folder on the removable disk, before deleting the old backup files. There was not enough space on the disk (size) I was using.
I created a cron job and put it in /etc/cron.d with a script in /opt/scripts/..., which mounts the drive and deletes the old backup just before the new full backup commences. It works quite OK.
I realise this deletes the old backup before the new one has completed, but I'm happy to forgo that in order to use the available hardware.
In /etc/cron.d/deletebkp1
30 1 * * 3 root . /opt/scripts/deletebkp1
In /opt/scripts/deletebkp1
umount /mnt/smb
/bin/mount -t smbfs //stationXX/bkp1 /mnt/smb -o username=XXXXXX,password=XXXXXXXXXXXXX
rm -f -R /mnt/smb/servername.yourdomain.com/
rm -f -R /mnt/smb/tmp_dir/