Note that the current version has a problem with the database directory growing a lot, this will be fixed in the next point release.
2011/4/27 Nick Hall <firstname.lastname@example.org>
Gramps does not have this functionality.
> I have been
> used to having the data base reminding me every two minutes (or what
> ever I set it for) to save my information and it would automatically
> save to a backup in my document folder which was then being backup to an
> external hard drive.
Because Gramps saves on OK clicks, so no need to remind one to safe. If you kill the Gramps process you will see everything you did is present on startup.
Keeping a backup on the same disk is not very usefull. Best is to use a backup client to backup your database directory and all your media files on a regular basis to a safe place.
Alternatively, you can run a script to export your family tree to a .gramps file (much, much smaller than a complete database with indexes) and back that up, gramps can be controlled without GUI.