i should have explained it a bit better.Ok one case that takes two mbds(1.5ghz with 2gb ram)each has sooftware raid so pretty useless.To each mbd there are 2x 1Tb sata hdds.
The issue being it can see more than 1Tb raw before its configured as a mirror.So this means that if you wish to use open-e software to mirror you'll never be able to have more than 500Gb,shame as the limit is 1Tb.I could get some hardware raid cards but this just adds to the costs.The mbd is VIA iDOT PC3500G PC-1 Mainboard - 1.5Ghz C7-D
, seem to run ok a bit slow on GUI interface but otherwise fine.
The reason for the low power itx kit is this will be going into a data centre and power is becoming more of an issue and pretty expensive