Hi. My team supports multiple standalone SQL servers and AlwaysOn clusters to host our customer DBs. Our on-prem standalone instances are typically dedicated to DB(s) for one customer app. Our on-prem clusters host multiple SQL instances. Clustered instances each host one or more availability groups. Some of the clustered instance are shared by multiple unrelated application DBs, and some are dedicated to specific application DBs.
What strategy do you use to deploy managed instances in your environment? I mean, how do you distribute multiple DBs to MIs? Let's assume initially a single subnet with max IP address space (which I think is 256 minus 5.) Also say that you support DBs for multiple unrelated client apps. Do you share one MI for multiple unrelated DBs? Do you dedicate one MI for each app DB? I guess, bottom line is how do you decide to deploy a new MI?
As far as architecting the subnets, do you deploy:
One MI in one subnet (in one vnet)?
Multiple MIs in one subnet (in one vnet)?
Multiple MIs in multiple subnets (in one vnet)?
Multiple vnets? (We're not likely to get allocated multiple vnets.)
We're aware of the MS articles that give calculation for subnet IP address space. However it is the deployment strategy I'm asking about.