Re: Some of us have been saying that for years
Hi all, Dimitris from HPE Nimble here (recoverymonkey.org).
Disk is indeed here to stay, but this doesn't mean ignoring AFAs is wise. What Infinidat is doing is akin to the saying "to the man with a hammer, everything looks like a nail". We get it - they have a decent hybrid.
Nimble (and others) have incredibly efficient and scalable hybrid systems, but also we have AFAs for the people that can't tolerate any latency variations due to the data not being in cache. Because 90% cache hit rate means those 10% of I/Os have to come from 7,200 RPM disks, with the latency that implies.
We can replicate from AFAs to hybrid to save costs, users aren't required to have all the same type of storage this way. Or have mixed hybrid + AFA clusters, with non-disruptive data movement between cluster members.
And with the Nimble ability to inline dedupe and compress for hybrid and AFAs (dedupe is now available for hybrid with Nimble OS 5), the price delta between hybrid and AFA becomes wider, not narrower. Yes, disk is here to stay.
And future very large capacity disks (both spinning and SSD) is one of the reasons Nimble RAID is Triple+ (5x more resilient than plain triple parity, and many orders of magnitude more resilient than other RAID types).
Still, I admit Nimble made a mistake to delay coming to market with an AFA. Our rationale was that the hybrid was SO GOOD that people didn't need an AFA. Sound familiar? :)
Yes, when one can cluster together 4 Nimble hybrid engines (each with 2 controllers) and enjoy huge capacity and performance in a single pool, it's easy to think an AFA is not needed. After all, that configuration could be set up with 400TB of cache, surely that's enough? :)
Ultimately, it was a mistake and the stock market punished us heavily for it.
I've presented in the same room as Brian from Infinidat, his entire thesis was that AFAs are unecessary.
If we are having these arguments we are not discussing things customers actually care about.