Here's how SBackup satisfies my requirements:
- SBackup has a modicum of network awareness; it can backup over an SSH or FTP connection in addition to a local directory.
- SBackup can do incremental and full backups. By default every backup (except the first) in SBackup is an incremental backup. The administrator can specify a schedule for full backups, such as a full backup every 21 days.
- SBackup has pretty good scheduling. The frequency of full and incremental backups can be controlled. A purging schedule can also be set up, for example: keep all backups for the last week, keep one backup a month for the last year, keep one backup every 6 months for years before that.
- SBackup's backups are software independent. This was a major problem I had with DAR, which I was using before SBackup: DAR archives couldn't be read without DAR. SBackup just uses tarred, gzipped files. So I have no worries about how I'm going to access the files in backup if SBackup is discontinued or unavailable in the future.
- SBackup doesn't have encryption, but right now this is not crucially important to me.