Both ZFS and WinSvr offer "real" dedupe. One is on-write, which requires a significant amount of available memory, the other is on a defined schedule, which use

Both ZFS and WinSvr offer "real" dedupe. One is on-write, which requires a significant amount of available memory, the other is on a defined schedule, which uses considerably less memory (300MB + 10MB/TB). ZFS is great if you believe you'll exceed some threshold of space while writing. I don't personally plan my volumes with that in mind but rather make sure I have some amount of excess free space. WinSvr allows you to disable dedupe if you want (don't know why you would) where as ZFS is a one-way street without exporting the data. Both have pros and cons. I can live with the WinSvr cons while ZFS cons (memory) would be outside of my budget, or would have been at the particular time with the particular system.