A small 20 person company wants a file share that everyone can access which has versioned file level backups. We don't plan to use the versioning often but we want it there if we need it. We already have a volume level backup occurring every hour to an external system. We're mostly using debian linux for our file servers and linux or Mac OS X on the desktop.
What are some good free open source solutions for automatic versioned file level backups in a file share?
Is the best solution something like a version control system, SVN or Git etc, which makes a new commit every time a file is changed?
Is using ZFS for this a good idea? I've read ZFS can take snapshots but from what I read they're volume level snapshots and not file level snapshots and from what I read you set them up like a cron job to take place every n minutes instead of every time a file is changed.
Thanks in advance.