(cheap) backup options for RHEL 4

hello all...
i have a client who is wondering about backup options for their
redhat servers.... its a small business... only about 5 RHEL servers
(probably a couple hundred gigs each, tops)... they just bought a
SCSI LTO3 tape drive....

what would be a good, cost-effective, easy-to-admin backup solution?
they don't need any enterprise-level stuff (no veritas)... (are the
legato products for linux expensive like veritas netbackup?)

are there any good open-source solutions? (is there anything other
than tar, cpio, dump, etc.. that i'm missing?) or at least LOW-cost?

whats your opinion?

thanks in advance!
--cc

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