it's not the same, notice I wrote r6gd, these are the ones with nvme, i'm looking just at those. I do not need all the space that i3en gives me (and probably won't be able to use it all due to memory usage, or have other issues just like you mention), so the plan is use the big enough r6gd nodes, such as r6gd.8xlarge, it has 1.9tb nvme, it should good enough for my needs (I would also add that a big chunk of the data that is not read that frequently, so I might be ok with putting a specific set of tables on EBS)
We are currently running with i3 servers, as you mention, they are indeed the sweet spot, but we are looking to move to bigger nodes. On Mon, Mar 1, 2021 at 2:16 PM Erick Ramirez <erick.rami...@datastax.com> wrote: > The instance types you refer to are contradictory so I'm not really sure > if this is really about Arm-based servers. The i3en-vs-r6 is not an > apples-for-apples comparison. > > The R6g type is EBS-only so they will perform significantly worse than i3 > instances. R6gd come with NVMe SSDs but they are disproportionately small > compared to the CPU+RAM they have. For example, a r6gd.2xlarge which has 8 > cores + 64GB RAM only has a 474GB NVMe SSD so they're not a good back for > the buck. > > On the other hand, i3en instances are intended for dense storage. I'd > discourage you from choosing this type since it will be tempting to have > dense nodes and are problematic when it comes to operations such as > bootstrapping, decommissions and running repairs. For example, an > i3en.2xlarge with 8 cores + 64GB RAM can potentially have 5TB of disks (2 x > 2.5TB NVMe SSDs). > > In my experience, i3 instances are the optimal choice such as i3.2xlarge. > I think 8 cores + 61GB RAM + 1.9TB NVMe SSD is the sweet spot for price and > performance. Cheers! >
