Back in 2005 I've used Bacula to setup a distributed backup system for a big company. I don't work there since years, but AFAIK it still runs well and manages around ~50 (both servers and desktops running different operating systems).

Yes it's hard to approach (we spent ~2 weeks to learn and test it before deploying in production) but it had the features we needed:

* scheduling

* retention policies (store for 1 year then rotate, multiple tapes, etc...)

* backup on DST tapes

Perhaps, if you just need to backup a single server, Bacula isn't the right solution or, at least, is overkill :-)