Hi Jeffrey Not sure if you were addressing Peter specifically or the list in general, but I'll answer none-the-less :)
I have 23 entries in 'volume efficiency show -state enabled', and of those, 14 are inline-only policy on SSD. None of those are being SnapMirrored. Of the remaining 9, 4 of them are being SnapMirrored to our DR. Of those 4, 1 of them is a constantly lagged 20t volume previously mentioned. The other constantly lagged volumes are not being deduped or compressed.
My rough guesstimate is that disabling this global throttle and leaving the SnapMirrors running overnight has transferred more snapshot data from these lagged volumes in less than 24 hours than in total from the previous month or maybe more. The tradeoff I am seeing is increased node CPU utilization as well as an occasional small uptick in latency to NFS clients.
I wonder if as filer hardware gets more powerful and enough evidence has been brought to light, this global throttle can be disabled by default or at least not be as aggressive - the snapmirror throughput increase is so significant that if I didn't see it myself I'd guess that someone was reading numbers incorrectly.
Ian Ehrenwald Senior Infrastructure Engineer Hachette Book Group, Inc. 1.617.263.1948 / ian.ehrenwald@hbgusa.com
________________________________________ From: toasters-bounces@teaparty.net toasters-bounces@teaparty.net on behalf of Steiner, Jeffrey Jeffrey.Steiner@netapp.com Sent: Tuesday, January 31, 2017 2:30:35 AM To: NGC-pdg-uow.edu.au Cc: toasters@teaparty.net Subject: RE: super secret flags
Thanks for all the feedback, this definitely appears to be a gap. This parameter wasn't intended to be required outside edge cases, but it seems that "edge cases" is way too narrow.
I have a question - what is your use of post-processing compression or deduplication?
There seems to be a few other cases where a lot of post-processing work was creating contention with snapmirror operations. Without going into too much detail, they both run as lower-priority tasks to ensure they don't interfere with "real" work like host IO operations.
If that's really the context then we need to update the KB article so nobody else ends up chasing a network or disk latency problem that doesn't exist. I'd imagine there could be other lower-priority tasks that could disproportionately mess with snapmirror transfer rates too. This may contain confidential material. If you are not an intended recipient, please notify the sender, delete immediately, and understand that no disclosure or reliance on the information herein is permitted. Hachette Book Group may monitor email to and from our network.