Hi Hirantha, (answers below) My questions are: If IDE HD fails, (OS in IDE) can I reinstall OS again in another IDE HD, and use disaster recovery to run exchange2k & restore the backup; will this work? which DR are you refering to? It sounds like rebuilding the whole server, which is of course almost always possible. Will this reduce the server performance - Installing ex2k in mirrored volume? Depends, software mirror (OS) yes, hardware - depends how you set it up. SCSI won't take any performance hit, 2 IDE drive on seperate channels shouldn't (most modern controllers won't), and 2 IDE drives on the same channel will - although very small. Do I need to setup page files on Mirrored Volume? No, especially in your planned setup. Or I'm Nuts? You have to be in IT! But seriously, the plan you have is not a very good one. If you tell us what hardware you already have (particularly SCSI and hardware RAID) we can recommend something much more reliable - maybe without spending much more money. Jamie.