Quick and simple snapshot backuping using rsync
The 3-2-1 rule can aid in the backup process. It states that there should be at least 3 copies of the data, stored on 2 different types of storage media, and one copy should be kept offsite, in a remote location.
- Wikipedia on Backup
References:
- https://en.wikipedia.org/wiki/Backup
Step 1: Make a rsync snapshot
We first make a snapshot of whatever folder you are interested. In this example, we take a snapshot of the home directory (/home/) to a mounted external device mounted at /mnt/backup.
rsync -avhux --delete /home/ /mnt/backup/snap-latest/
The --delete option is used to ensure it's a literal snapshot and unwanted files are also removed. Ideally, we should periodically and automatically perform this command, e.g. using a cron job. Add the following line by editing the crontab, crontab -e:
0 12 * * 6 rsync -avhux --delete --info=stats2 /home/ /mnt/backup/snap-latest/ >/mnt/backup/logs/snap-"$(date +'\%Y\%m\%d')".log 2>&1
We now scheduled it for saturday (i.e., 6) at noon and also log the transfer to a log file with a timestamp.
Step 2: Make a compressed backup
Once, we have a snapshot clone of our /home/ dir, we can also periodically make a compressed backup of the snapshot. All we need is to tar and compress the latest snapshot with the timestamp of the snapshot:
tar -cvzf /mnt/backup/snap-"$(date +'\%Y\%m\%d')".tgz --directory=/mnt/backup/snap-latest/ .
Ideally, we can now make a backup of the compressed file to another backup device. Like with rsync, we can schedule the compressing and ideally we do it once a month:
0 0 1 * * tar -cvzf /mnt/backup/snap-"$(date +'\%Y\%m\%d')".tgz --directory=/mnt/backup/snap-latest/ . >/mnt/backup/logs/tar-"$(date +'\%Y\%m\%d')".log 2>&1
We perfom the command again with cron, at first day of the month (1).