Hello,

We are considering the addition of a Flash Pool to our 2240 arrays. We currently run ONTAP 8.1.3 7-mode with no plans of upgrading to 8.2.x. Per the docs, 8.1.3 allows us a total Flash Pool SSD cache capacity of 400G for the entire 2240 array.

We're told we can't get 100G drives so our next best option is 200G drives. The problem with using 200G drives for the Flash Pool aggregate's SSD cache is that we'll be limited to a single 200G SSD drive to be used for cache behind each 2240 controller.

Why is the is a problem? Well, the Flash Pool TR and FAQ touches on the possibility of the SSD cache becoming a bottleneck. I'd imagine this is more likely with just a single 200G data disk in the RAID-DP SSD cache. What makes it more of a concern is NetApp stating that a single SSD drive is capable of roughly 5,000 IOPS (I assume at a 4K 70r/30w workload) while the 2240 is capable of 15,000+ IOPS while processing the same workload.

Note: We'd like to flash pool enable both controllers in the array and the SSD cache is required to be RAID-DP as the aggregate is RAID-DP and we are running 8.1.3.

My questions:

Are my concerns warranted?

Has anybody had good or bad experiences with Flash Pool and the 2240 arrays?

Anybody running a similar configuration to what is outlined above?

I'd love to hear about your experiences.

Thanks, Phil