So, I know there are a lot of great tools for analyzing current resource utilization and so on, but that's not what I'm looking for.
What I'm trying to figure out is the best way to plan how much hardware I need to buy (for simplicity, let's stick to just racks of servers, not networking and so on).
I know what our planned VM allocation will be for when we start off, but if I know I'll have X web servers, Y app server and Z DB servers (and I know what RAM, CPU, storage and network I want to allocate to each), is there a good way to figure out, "Ok, I need N blades with the following hardware specs...? I assume it's whatever my VMs need plus some overhead for the hypervisor and host OS plus some engineering wiggle room, but I'm hoping someone has a slightly more robust approach.
Every time I tried googling I got people trying to advertise tools for analyzing an existing install, which isn't what I'm looking for.
Note that this is NOT a generic capacity planning question as the VTC moderator closed me for. (Can you help me with my capacity planning?). I fully understand benchmarking and growth over time. What I’m specifically asking for is much more bounded than that: given that I already have estimates what virtual server resources I need, how do I translate that into a rough estimate of initial hardware to purchase? I recognize that once I’ve done that I’ll need to do the real work of benchmarking performance, balancing my VMs across racks and all that.