[CentOS] Incremental backups?

So I thought I'd get a head start for next week -

I have a low-power Linux box that has a few samba shares mounted, and 
limited hard disk space.   This box is connected to a tape library via 
SCSI card.

I want to find the best way to create a full, then incremental backup of 
the samba mounts, directly to tape.  Some of the samba mounts are 
appliances that cannot run any special client/agent.

I'm looking at tar as an option, with its --incremental switch.   Bacula 
uses a mysql database.  I tried setting it up and it was not so easy, so I 
opted to use my time for other tasks.  Same for Amanda.

I would use dump, but samba connections are not device files.

How about rsync?   The tape library is LTO3 with hardware compression 
available.  Google searching just now doesn't make rsync directly to tape 
too hopeful.

What are the simplest options for incrementals based on date/time 
modified?

Thanks.

Scott