I wish to build A backup server in case of server crash. Do i need to use same mobos specs. ie. same chipset as original and cpu bus speeds, memory types. ect. Server running 7.2, application is POS, Synchronics Counterpoint, (radiant-retail).

Linux will autodetect used hardware and chances are good, that you may run your os with new hardware. Nevertheless you are using quite an antique Red Hat release and you probably have no support for it anymore.

Of course if the new hardware is close to the old one, you have better luck that everything quite runs the same.

However I would evaluate a migration of the software to an actual RHEL release or would test alternative backup software if possible.

By "backup server" I take it that you do not mean "a server for running back ups" but something more like "a hot (/warm) swappable server, to fulfill the same tasks as the primary server".

...absolutely... Fortunately, this presents an opportunity. Roughly

• Get new hardware
• Install recent software
• Configure everything and test
• Bring old server up to new software standard and use as hot swap server

Note that you should not underestimate the process of going up to the new software from your current ancient version. It might, if you are lucky, be trivial, but you still have to do the testing, because you can't rely on that. After all, its not just a small incremental upgrade that you are taking.

Random thoughts:

• No, you shouldn't need the exact same h/w.
• Definitely upgrade your OS.
• Remember CentOS is a $0 equivalent to RHEL.
• Don't be tempted to use Fedora on a real production server.
• The upgrade process may take long enough, because of thorough testing, that you may need to make a temporary back up server along the lines of your OP.