Since Apple stopped selling the Xserve on January 31, 2011, Server rooms are faced with a devil's bargain: the powerful Mac Pro server has great performance and the Mac mini has great economy and both make nice servers with Apple's $20 OS X Server app . But neither was designed as a rack-mountable modular system with the redundancy of available parts kits.
A possible solution is the R.A.I.S. suggested on
Take one Mac mini server configure as you like and enable its boot drive as a RAID member.
Boot the other Mac mini server into Target Disk Mode.
Connect them with a FW-800 cable (or ThunderBolt cable if the equipment supports it).
Add the TDM mini to the mirror that the boot drive is in.
Now if Primary Mac has blown a logic board, power supply, or drive you simply disconnect the TDM cable and start up the Secondary Mac without Target Disc Mode.
Voila! Redundancy! Costs less than an Xserve spare parts kit, too!
Listen to Alex Narvey talk about R.A.I.S. on the Command-Control-Power podcast:
This web page provides some resources for getting your RAIS together.
Warning: No warrantee of the RAIS concept or its fitness for use is express or implied. Apple, Mac mini, and Mac OS X Server are trademarks of Apple, Inc. All other 3rd party hardware and software are trademarks of their respective owners.