Re: Postgres IO sweet spot

That's an expensive way to provide some HA. What's the business requirement? How does that tie into Postgres? Might be able to do it in other ways.

We used to run a SAN shared between our host servers, but this was replaced with Storage Spaces. I think they don't trust Postgres native HA capabilities and want some hardware guarantee.

Yikes! Yes, SSD would be a big win. It's orders of magnitude faster, and just removes so many problems.

I assume it will help, but I fear however that the overhead with a 3 way mirror is not going to be solved with just adding SSD. I'm trying to get them to rather deploy direct attached NVME/SSD to each Host and then use PG HA from there.

Sorry, I have no numbers to provide you there, but I cannot imagine any amount of tuning is going to be as big a win as going to SSD.

It does take a lot of convincing and arguing though, so concrete number help get the point across.

Thanks for the response