backup system for RHEL

[ESGLinux]

Hi all,
I´m planning to use a server as centralized backup system. I need to backup
windows and linux system.

I have seen that RHEL comes with amanda, but I don´t like it very much, so
which system do you recommed me?

by the way, I need to make backup of vmware and xen images, but I don´t know
how to do it. Do I need to stop the images? which is the mechanism to make
this task?

Thanks in advance

ESG