What is the best way to backup 2 servers into 1 backup server

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I would like to have two RH7.3 servers back-up every 8 hours into third RH7.3 server's 
hard drive. I was thihking about mounting file systems of two servers into third 
system via samba  and do sopy function via cron(yes, I am fairly recent NT convert), 
or try something else.
Any ideas?
I just want the back-up system to check if file is newer than most recent copy on the 
back-up and if it is, make a copy and overwrite the old one. Bandwidth is not an issue.
Thanks.
Anything with a GUI helps.