Deduplication is not stabilized, user should be warned on post emerge messages about it.
My apologies for not getting to this sooner. I was preoccupied with Hurricane Sandy when this was filed and I am still catching up on the backlog that caused. I can easily think of several other things that could merit warnings (e.g. disabling checksums, putting SLOG on a tmpfs, etcetera). That information should be part of more comprehensive documentation than a post merge message. In the case of data deduplication, it does work provided that you understand its limitations. The following two links are fairly informative: http://www.zfsbuild.com/2011/11/18/dedupe-be-careful/ http://www.c0t0d0s0.org/archives/7271-ZFS-Dedup-Internals.html I do not plan to add stable keywords until I have written comprehensive documentation and fixed several bugs in the upstream bug tracker. With that in mind, I do not think adding a post merge warning would be of much benefit. If you feel strongly about this, I would be open to reconsidering it if you would provide a precise explanation of why "Deduplication is not stabilized" and propose what that message would say.
