No after your explanation I think that better sells the idea of a new cluster a little better. The original thought process I was under was basically in 2 pieces 1) KISS keep it simple, less provisioning of new VM hosts etc., 2) I wanted to understand why when sold a "scalable" solution originally how it could be so complex to access that original scalability model (that’s my own OCD kicking in there).
The existing vCenter will run multiple Clusters so no complication there. Citrix will work across Clusters, just add the new location into Studio. I’m assuming you already have the correct vSphere licenses (Enterprise Plus) for your existing Cluster, but you’ll obviously need additional vSphere Enterprise Plus licenses for the new Cluster, unless you’re running (vSphere for Desktop). So I’m not initially sure what the issue is with creating a new Cluster, and it’s actually not a bad idea to have more than one …
Good call we have standard licensing on the existing nodes right now so we’ll upgrade to Enterprise Plus. Your explanation makes sense to me and the idea of a new cluster based on that is no longer a bottle neck in my mind now.
What are the Specs of your existing HX220 Hosts? (PSU Rating / CPU (Cores and Clock (or model number and I’ll look it up) / RAM / Disk / Network). Have you checked to see if you can fit 2 T4s in them (just to make sure 2 PCIe slots are available)?
Each node is HX220c-M5sx, dual 2.6 6132 processors, 756GB (766) max ram, 6 x 1.8TB drives. I looked up the specs here https://www.nvidia.com/en-us/data-center/resources/vgpu-certified-servers/#utm_source=shorturl&utm_medium=referrer&utm_campaign=grid-certified-servers
So its good for 2x T4 per node, and it looks like the HX240x M5 can take 6x per node ?
Hosted Shared Desktops (XenApp) - Don’t use Windows 2016, it’s really old! If you’re building these XenApp VMs from scratch, then you should be using the latest version of Windows 2019. If you’re running “Microsoft Volume Licensing” then there’s an April 2020 fully patched version sitting on the VLSC Portal ready for use. Regarding XenApp VM specs, now that you’ve mentioned which applications you’re running, the M10 is no longer an option for you regardless of any Server. The Applications you’ve listed are also reliant on CPU Clockspeed, the higher the better and typically nothing less than 3.0Ghz, so make sure any new Server purchases have a 3.0Ghz+ Clock. You should be looking at the T4 at a minimum. Using vGPU, you’ll need the 8Q Profile (Not 8A) for each XenApp VM and you’ll get 2 of those per T4. This will require QvDWS licensing (because of your Applications), but as you’re an Educational facility, speak to your IT distributor and you will be able to get EDU pricing for the vGPU licenses (it makes a HUGE difference). The reason this is important, is that vGPU is licensed per CCU, so if you have 250 CCU, you’ll need 250 QvDWS licenses. And yes, you need QvDWS licensing with these applications, vApps won’t give the performance needed. Regarding CPU and RAM, assuming you have adequate resources and can retro fit 2 T4s into the HX220, you’re effectively splitting the Server into quarters to support 4 XenApp VMs.
We are definitely looking at server 2019 for brand new builds.
Start with the following specs for each VM and then modify 8 vCPU / 32GB RAM / T4-8Q. This spec will typically support 20 – 25 Users (sometimes more / less), but this is application dependant and the applications you’re planning to run are typically delivered using XenDesktop (Not XenApp) to give consistent performance, so your XenApp density will probably be lower, but it depends how the Applications are used. Start with those specs and see how you get on.
Those are spec’s now, except we are at 36GB RAM and don’t have a vGPU profile. Same mindset as you suggest need to try it and see what the real user experience is like and so on.
you should be looking to run a POC for the XenApp and XenDesktop VMs so you know what size profiles you need (CPU / RAM / vGPU). Then you can spec your new Servers correctly to fit the maximum amount of Users on them and allowing a little headroom for future performance and additional application requirements. There’s nothing worse than buying a new platform to meet your current requirements, then in 6 months or a year later when new applications are installed, realising that you didn’t allow enough performance headroom to support them.
What is your total planned CCU density for XenApp & XenDesktop? 10 servers sounds a lot just to support 250 CCU …
I think this is solid advice, running a PoC with some T4’s is the way to go and then make expansion plans based on outcomes from that we’ll have a better idea. We really don’t know our CCU count, we have around 500 physical workstations currently but the number of unique users is 4x times that amount but they are not all using them at the same time so this expansion to measure actual usage patterns is somewhat of a guessing game for us at this point as well.
Unfortunately I can’t comment on GPU EOL / EOS. All I’ll say is that it’s not a good idea to buy and build a new Server platform around a GPU that’s 4 years old. There are technical reasons why you wouldn’t want to use them as well due to their architecture. Basically, stick with the T4 as a minimum, design around that and you won’t go too far wrong.
I think you sold me, if the M10 is 4 years old it’s pretty sure it will be discontinued or replaced in short order vs the T4 which is from 2018.