Gotta boost the signal on this. My friend Nick Rintalan from Citrix Consulting has put together a new ‘best practice' (or leading practices for the lawyers) update that I feel it's important for people to see!
New Best Practice(s)?
Here are some of the highlights of the article, sorted here by what I feel is most important for you to read:
- PVS and Memory Buffers. Yes, yes, for the love of all that is holy, yes. I haven't yet deployed for validated the Write Cache features now in MCS, but I can tell you from experience that XenApp with 2-4 GB of RAM cache with failover to disk has been giving roughly 20-30% faster logons and overall better experience for most of my customers.
- Protocols (as in HDX). One of my primary frustrations for quite some time now is that Citrix XenDesktop ships by default with a protocol that has a good experience on LAN but tends to be problematic at distance. H.264 is great for video, but frankly I hate it everywhere else. I think it almost singlehandedly ruined things for Citrix since PCoIP can perform better than this hog (my opinion). Thinwire and even the legacy encoder, however- actually deliver on the promises and need to be investigated in nearly every single use case I see. So I agree with Nick- use the policy templates included with 7.6 u3 and above (including LTSR) as a starting point. Odds are good you won't be disappointed. When I say ‘use' here what I mean is remember that you can apply these codecs on a per user basis, connection basis or even per delivery group- meaning filters are your friend! It is perfectly acceptable to have multiple codecs going for various use cases. One size nearly NEVER fits all, so test these out!
- vSphere Cluster Sizing. Number 3 on my list right now. You need a dedicated resource cluster for Enterprise workloads- but honestly- for XenApp workloads, consider more hosts per cluster. You should be using bigger VMs anyway, so the number of managed VMs is about the same- just more computing power. CCS is seeing 24+ hosts per cluster be just fine in XenApp. For XenDesktop with more than 5000 VMs- I will add here that a dedicated vCenter may save you a lot of pain… my opinion, and of course… you guessed it. TEST!
- XenApp CPU Over-Subscription. Seriously. The “1.5x” thing needed an update so I'm glad to see some clarification here. In all things- I still encourage practical testing instead of just implementing something because “Citrix said to.”
- PVS Ports and Threads. Those of you who know me know I bang this drum a lot- so here's some backup for what I'm saying. The defaults are not good enough. Good design is still required!
- Farm Design. You're probably like me and are coming along kicking and screaming from XenApp 6.5, which most would agree has been the “Windows XP” of the Citrix world. It just hasn't been this good yet, and I still feel 7.9 doesn't have true feature parity… but as Nick describes, they are getting there. As always… TEST, TEST and then TEST some more before you implement zones with FMA!!!!
- XenMobile Optimizations. I guess we have to talk about it. XenMobile is here to stay, so best to not take the ‘out of the box' experience there either.
Give it a read and let me know your thoughts… but most importantly- don't forget to share this!