I have read a lot of information about planning RAM requirements forZFS deduplication. I've just upgraded my file server's RAM to support some very limited dedupe on ZFS zvols which I cannot use snapshots and clones on (as they're zvols formatted as a different filesystem) yet will contain much duplicated data.
I want to make sure that the new RAM I added will support the limited deduplication I intend to be doing. In planning, my numbers look good but I want to be sure.
How can I tell the current size of the ZFS dedupe tables (DDTs) on my live system? I read this mailing list thread but I'm unclear on how they're getting to those numbers. (I can post the output of
zdb tank if necessary but I'm looking for a generic answer which can help others)