Rsnapshot is a perl based filesystem snapshot utility for making backups of local and remote systems.
Using rsync and hard links, it is possible to keep multiple, full backups instantly available. The disk space required is just a little more than the space of one full backup, plus incrementals.
Only SSH and rsync are required on the remote host to be backed up.
If you wanted to off-site backup a QNAP NAS, you would set up an external server to run rsnapshot to pull data from the QNAP. If you are using the QNAP as a backup destination, then rsnapshot should be installed on the QNAP.
There is an extension with GUI called Rsnap.
- Install ipkg
- ipkg install rsnapshot
- Set up config file
- Set up crontab to call rsnapshot
Rsnapshot relies on a machine being backed up to have an open port for SSH, and SSH installed and set up for key-based login. Since backups are pulled to the server, the rsnapshot server will have SSH keys for all computers which it is backing up, therefore if the rsnapshot server is compromised, the SSH keys are compromised and the attacker can log into those other systems. Use with caution.