Regarding specifically your request for incremental backups, I suppose the first question is to ask how you define the word incremental. Long ago there were two terms used in backup strategies: differential and incremental. A differential backup made copies of files that had changed since the previous backup. A full restoration required restoring each differential backup. An incremental backup copied all files that had been modified. A full restoration required only restoring that one backup. Definitions change and I think those two words are used differently today. Further, the file systems used in Linux-based systems do not use an archive bit, common in Microsoft file systems. Linux-based file systems do use modification time stamps, which serves a similar purpose.
Rsnapshot uses rsync and hard-links to backup files. Because rsync and hard-links are used, each backup is a difference between the previous backup. A rather fascinating and efficient process.
I use rsnapshot in a comprehensive backup strategy. Although originally written for my Slackware environment, the same strategy can be adapted easily to Debian.
You can read more here:
A Backup Strategy
In my backup strategy I have cron run rsnapshot every three hours to backup my most important configuration and data files. I manually run rsnapshot weekly to perform a full backup. I have additional computers here in my home LAN and I run another rsnapshot backup of those systems. However, those systems do not change anywhere near as much as my primary office machine. Therefore I run that full backup about monthly.
I use a different rsnapshot config file for each backup routine.
For the manual backups I use a 750 GB SATA drive and a removable drive bay. The SATA drive is hot-pluggable. I store 26 weeks of weekly backups and about 6 remote backups.
A critical test is whether I can restore files from this backup strategy. I did this just the other day when I restored a copy of a CD ISO image I wanted to play with that I hadn't used in a while. I had deleted the local copy but the backup provided me a means to restore the file without wasting ISP bandwidth and waiting 45 minutes for the image to download.
I haven't reviewed the how-to in a long time and I would be grateful for any helpful comments. Feel free to ask questions too.
