On an AFF platform, when you check the box on a volume to run post-process efficiency operations is for deduplication only.
I think the previous poster may have been getting at the ability to run both post-process deduplication AND compression on an AFF (which, is currently not possible).
This is where things get a little interesting in that in 7-Mode and on FAS/Hybrid environments, the post-process compression operations are secondary (32K) vs. adaptive (4K). You can do secondary on AFF but only inline and as a replacement of the default of inline adaptive (not to mention having to undo all current savings to flip from one to the other, then having to re-run things).
I admit that having the same ability across both FAS/Hybrid and AFF environments would be nice, even if it's a means to just run secondary background jobs just to catch anything missed coming inline, but I suppose that's where Compaction is supposed to pick up the slack.
I've made some good use with running the background scan for migrated / existing data for adaptive compression savings ("-scan-old-data") in some cases.
The issue I'm dealing with currently, however, is with Exchange and migration via mailbox moves from 7-Mode to AFF. The efficiency savings on the AFF side aren't pretty, and are actually worse than just having deduplication enabled on the 7-Mode side. I'm wondering if there's a setting someplace with the LUN that's affecting the savings (thin across the board, 0 fractional reserve, etc...).
When mailbox moves were going on from 7-Mode LUN to AFF LUN, efficiency stats on the AFF volume reported back that 0 inline compression attempts had been made on both the DB and Log volumes. Is this because of the nature of Exchange and that process (where it's just a ton of logs that move over then write / commit tot the DB)? Different than something like a Storage vMotion where you're moving a ton of blocks?
Anyone have any similar Exchange-related experiences they can share?
I'm about to go run the post-process adaptive scan just for the heck of it to see if I gain anything. Figure no harm in trying...