On 2020-06-30 14:41, Parisi, Justin wrote:
2 aggrs give you more available WAFL affinities (cpu threads for parallel write metadata operations) which will help performance -
True that. (theoretically more threads inside WAFL for parallelism).
But, unless you start over so to speak and "stripe" everything across everything with new FlexGroup(s) (even across two nodes, that's quite possible) you will have to make sure to divide up the workload (= FlexVols) somehow between the two Aggrs w.r.t. the IOPS and the nature of those IOPS, instead of the way you have divided it up now. And you're not really going to do that, I don't think. As it would pretty much put you back to square one, or even more cumbersome.
So in essence, having 2 Aggrs will in practice not give you any benefit you will ever notice unless your FAS8020 nodes become quite overloaded. What remains is the small risk that you can, rarely, end up in a sort of queuing state (with bad luck) during short periods where parallelism is decreased to the Aggregate level inside WAFL i.e. one (1). In that situation iff you had "half" of your workload on the other Aggr, that one could then continue as normal. But that's the only advantage in practice really, that I can see
Upgrading to 9.7P5 on your system will also make things considerably better w.r.t. these intricate WAFL parallelism complexities. There are lots of improvements over 9.1Px that's for sure. Tons of hard and clever work has been done by NetApp R&D there to improve performance and make it behave as predictable as possible. I.e. once you're at 96-99% CPU avg in your 8020 *that's* when things will be bad and everyone will suss that. Easy logic
So I second this:
Anthony Bar wrote:
9.7 P4/P5 is definitely the place to be right now — if your system can run it (check https://hwu.netapp.com to see) There are a couple ugly bugs in the GA 9.7 and P1-P3 but P4/P5 ironed those out and it's very stable, and there are a lot of performance improvements (esp. if you run on an AFF). The new low-end AFF (c190) is a really great deal price-wise too for a small deployment.
Cheers, /M