Hi, For the particular system in question, we have a 1.5TB "disk" (RAID 5) which is currently more than 75% "externally" fragmented. I am looking at several defragmenting tools such as Diskkeeper, PerfectDisk, etc. but I need to know in advance about how long it would take to defrag a volume this size so I can plan for down time. Certainly I don't expect an exact number, but I would like a best case to worst case scenario. I personally have not yet defragmented a RAID disk and am looking to benefit from those of you experienced with this sort of thing. Thanks!