At our office we have a Dell Poweredge 840 server that can handle 4 sata drives. There are two 160 gb internal harddrives hooked up to it. It is setup as raid 1. Then there is an external 160 gb hdd which creates a backup of the server or disk 0 using novastor. We want more hdd space. I am thinking of increasing the size to 500 gb of usable storage. That means that I need another 500gb hdd to for a raid backup and another for an external backup. What setup can i use so that the 2 internal 160 gb hdd's that we do have does not go to waste. Is this possible?: setting up the 2 internal 160gb hdds as raid 0. buying a 500gb hdd and setting up as raid 1 to mirror image the 2 160gb hdds. and then another 500gb as an external backup. but this would mean that i would have to reformat the drives which has all our info on it and it is time i cannot lose. How can i keep the 160 gb hdd that is being used on the server but add more hdd space and have it backed up with raid? if i add another hdd to the server, will this effect how Active Directory manages the users permissions as the added hdd will have more files on it which users will need access to. If i just set the added hdd as shared and give the specific rights to each user as it should be, will the server function properly this way? Any and all suggestions will be extremely appreciated. Thank you.