To download the calculator, please see the attachment on this post (also note that the calculator can be used for E2016 deployments as per this).
It’s been a long road, but the initial release of t...
Updated May 13, 2020
Version 8.0
Blog Post
Question on some calculator results I'm seeing after hearing your presentations at TechEd...
Looking at the differences between selecting Site Resilient Deployment = Yes with 2 CAS/MB multi-role servers in the primary datacenter, and 2 in the secondary datacenter in an active/active single DAG deployment.
With our settings, the role requirements indicate 96GB RAM for each of the 4 servers, in order to support losing both servers in either datacenter.
If I run the same settings against Site Resilient Deployment = No, still keeping a single DAG with 4 multi-role CAS/MB servers, allowing for the failure of any 2 of the servers (in the same datacenter), the calculator indicates 48GB RAM required.
I'm missing what the "special sauce" is in a Site Resiliency scenario that would necessitate double the RAM. In the site resiliency scenario, both datacenters are hosting 50% of the active user databases, so the servers are carrying the same 25% load in both cases in normal operation, with the possibility of hosting up to 50% of the load, should both servers in the other location fail.
In our case, our secondary datacenter is directly fiber connected and is essentially a remote extension of our primary datacenters, so while in a different subnet/AD site, there are no users resident in the second site. Because of this, I'm thinking that I should use the numbers for a non-site resilient scenario, with two servers in each location across a single cross-subnet DAG. Can anyone shed light on the different resource requirements here? Thanks!