Introduction – Please Read First
These questions are here to assist with ensuring that you’re gathering necessary information from a customer/prospect in order to put together an appropriate solution to meet their requirements in addition to capturing specific metrics from tools like Collector or RVTools.
This list is not exhaustive, but should be used as a guide to make sure you’ve done proper and thorough discovery. Also, it is imperative that you don’t just ask a question without understanding the reason why it is being asked. We’ve structured these questions with not only the question that should be asked, but why we are asking the customer to provide an answer to that question and why it matters to provide an optimal solution.
Questions marked with an asterisk (*) will likely require reaching out to a specialist/Solution Architect resource at Nutanix to go deeper with the customer on that topic/question. Make sure you use the answers to these questions in the Scenario Objectives in Sizer when you create a new Scenario. These questions should help guide you as to what the customer requirements, constraints, assumptions, and risks are for your opportunity.
This is a live document, and questions will be expand and update over time.
EUC – End User Computing
Basic discovery
1. What is the expected type of EUC workload?
Why Ask? Are we talking about VDI (Full Desktop), RDSH (Shared Desktop), Application Virtualisation (like Citrix Apps or Horizon ThinApp). Please keep in mind that you need to ask this question for every different workload the customer needs. In most EUC projects there is not just one type of user requirement. You will find a lot of mixed workloads, like persistent and non-persistent desktops as well as application virtualization.
VDI-Core licensing can help if the customer wants to run resource intensive VDI workloads, like developers or VDI with vGPUs and DR scenarios. For more information on VDI licensing check: https://docs.google.com/document/d/1VkFYvpOsAqmbwCwPWfGxg9bFhAmsPyANocn9rwG6eQQ/edit
2. Which vendor is used to manage and broker Desktops and Apps?
Why ask? The main vendors are Citrix, VMware, Nutanix. Every vendor has its own transport protocol, which makes a difference in CPU usage. Citrix = ICA, VMware = Blast or PCoIP, Frame = Frame Remoting Protocol.
3. What is the expected Operating System Version?
Why ask? Every new version of Windows has higher requirements on CPU and Memory. It can make a big difference, if an older Windows version compared to the latest version. Windows 10 Performance Impact Analysis: https://portal.nutanix.com/page/documents/solutions/details?targetId=TN-2113-Windows-10-Performance-Impact:TN-2113-Windows-10-Performance-Impact
4. What type of Windows license model is in use (KMS versus MAK)?
Why ask?Depending on the solution that is determined you may need to have one license model or the other (i.e. Frame requires KMS)
5. What Office version is used?
Why ask? For Microsoft Office it is the same issue, like Windows versions. Newer versions need more resources. Office 2019 Performance Impact Results from LoginVSI: https://www.loginvsi.com/login-vsi-blog/98-login-vsi/907-office-2019-performance-impact
6. What other applications will be used?
Why ask? The applications used are having have a strong impact on the CPU. There might be single-threaded applications, which need high clock speed. Or you run applications that are multi-threaded and need a higher core count.
7. What is the expected type of user?
Why ask? In sizer we ask for user types: task, knowledge, power user or developer. Every user type comes with a specific workload profile – memory, # vCPUs, vCPU:pCPU ratio, disk size. Sometimes the customer can give you details on the VM sizing, but not on the expected vCPU:pCPU ratio. Depending on the workload expected you can set the ratio. For more information read here: https://www.loginvsi.com/documentation/index.php?title=Login_VSI_Workloads
8. How many concurrent users will you have on that workload?
Why ask? Concurrent user defines the number of active users. How many VMs need to run at the same time. Our VDI licensing is based on active VMs. You can have more users in an environment, but they can share resources, if they don’t work on the platform at the same time. This can impact how you size compute and memory, but remember that storage may be needed for all possible users.
9. What provisioning method is used?
Why ask? Depending on the workload the VMs can be persistent or non-persistent. Persistent desktops will be treated like normal VMs. Non-persistent VMs will have a different storage footprint, since they are sharing a single boot disk and have additional write cache disks, which will be deleted after a VM reboots. Citrix uses MCS (Machine Creation Service) or PVS (Provisioning Service). VMware uses LinkedClones or InstantClones.
10. Where are the user profiles stored?
Why ask? Using our own Files solution we can provide storage for the user profiles. Today you will mostly meet FSLogix profile containers, which still need an SMB share to be stored on and loaded during user logon.
11. Do you need additional GPU support? * (This may warrant engaging with a Solutions Architect or EUC Specialist for proper sizing and configurations)
Why ask? In order to accommodate applications like CAD or requirements in number of monitors and high resolution you need to add NVIDIA GPUs. An overview of vGPU Profiles can be found here: Virtual GPU Software User Guide :: NVIDIA Virtual GPU Software Documentation https://portal.nutanix.com/page/documents/solutions/details?targetId=SN-2046_vGPU_on_Nutanix:SN-2046_vGPU_on_Nutanix
12. Are there any other special requirements?
Why ask? Does the customer need RF3? Block Awareness, Rack Awareness, Storage encryption or replication)
VM Details
1. How many vCPUs?
Why ask? The number of vCPUs impacts the performance of the VM and the density of the host. Solution Engineering found the sweet spot to be at 3 vCPUs for a Windows 10 desktop or 8 vCPUs for Windows Server based Desktops
2. What is the ratio between vCPU to pCPU?
Why ask? See question 6
3. What is the requested CPU size per User?
Why ask? How much MHz does every user need to run the workload? It is very rare a customer can answer this. It is more common in application virtualization environments, since a number of users share the same VM and its resources.
4. What CPU is currently in use?
Why ask? If the CPU currently used can handle, you could choose the same clock speed. But keep in mind in a virtualized environment resources are shared and you might have additional tasks running, like Files, which can impact the CPU.
5. How much Memory is required per VM?
6. What is the disk size?
Why ask? Depending on the provisioning method used you need the size of the Master Image (also called parental disk or Sandbox) and the Write Cache per VM. The write cache stores the temporary files written during the VM is active. For persistent VMs you need the disk size of the Master Image, which is then cloned into separate VMs.
7. Are you planning to use microsegmentation to secure your VMs? If yes, what solution will be used? * (This may warrant engaging with a Flow or Networking specialist or Solutions Architect)
Why ask? Position Flow on AHV or remember to size for a NSX appliance on every host.
8. Are you planning on using an App layering solution?
Why ask? This saves the customer the need to manage lots of different master images. With App layering you have one master image and when a user logs the system will automatically attach additional disks, which contain the required applications. We can use shadow cloning to make those disks available locally.
General supporting Infrastructure
1. What Hypervisor are you planning to use?
Why ask? Different Hypervisors have different needs. If the customer chooses AHV we need to plan for PC, if it is VMware we may need to accommodate vCenter and for HyperV we need SCCM.
2. Where will generic required services run?
Why ask? By generic services we mean AD, DHCP, DNS, Printing, licensing or application backend services. Some of them might be running in the cloud or on existing infrastructure. If running on the Nutanix Cluster take note of size and see Server virtualization questions.
3. Where will user profiles, home shares or App disks (if used) be stored?
Why ask? This is an opportunity to position Files. Usually customers today use a profile container to store user profiles. FSLogix is the most common solution used by customers, since it is included in their licensing. Please be aware that Files Services running on the same cluster do have a performance penalty during logon times.
4. What is your DR strategy?
Why ask? Every customer needs a DR strategy for their EUC environment. A great question to position Xi Nutanix Clusters on AWS, replication and our unique VDI licensing approach.
Also need to calculate additional resources in your sizing, depending on the customers strategy.
Citrix Infrastructure
1. Where do you plan on running your Citrix services?
Why ask? Customers can choose to run all Citrix related services (like Studio, Databases, Storefront) as service in the cloud, managed by Citrix or on premises. If the customer chooses to run the services on premise, he can still run it on a different infrastructure. If he chooses to run it on the same cluster, please size additional server virtualization VMs. Guidelines on VM requirements can be found here: https://docs.citrix.com/en-us/citrix-virtual-apps-desktops/system-requirements.html
If the customer chooses Citrix Virtual Apps and Desktop (CVAD) Service you still need an additional Windows server as Cloud Connector.
A typical on premise implementation would need the following servers:
SQL deployment. What type of HA? (Always On, SQL Clustering with WSFC)
StoreFront Servers (HA, N+1)
Citrix Desktop Studio and Director (N+1)
Optional Provisioning Server (PVS) (N+1)
Network Load Balancer
Global Server Load Balancing
Profile Management Infrastructure (File services)
AppLayering Infrastructure
Any Endpoint Management technologies?
Failure domain sizes (Prism Central sizing)
Dedicated Infra Management Cluster or part of the Citrix cluster
VMware Infrastructure
1. Where do you plan on running your VMware Horizon View Services?
Why ask? Customers can choose to run all Horizon related services as service in the cloud, managed by VMware or on premises. If the customer chooses to run the services on premise, he can still run it on a different infrastructure. If he chooses to run it on the same cluster, please size additional server virtualization VMs. Guidelines on VM requirements can be found here: https://docs.vmware.com/en/VMware-Horizon-7/7.12/horizon-installation/GUID-858D1E0E-C566-4813-9D53-975AF4432195.html
A typical on premise implementation would need the following servers:
SQL deployment. What type of HA? (Always On, SQL Clustering with WSFC)
Unified Access Gateway Appliances (N+1)
vCenter (N+1)
Horizon Connection Server (N+1)
Optional View Composer (N+1)
Profile Management Infrastructure (File services)
AppLayering Infrastructure
Any Endpoint Management technologies?
Failure domain sizes (Prism Central sizing)
Xi Frame Infrastructure
1. Will there be Xi Frame User VMs on premise?
Why ask? For the use of Xi Frame on premise you need to add additional server VMs.
Cloud Connector Appliance (CCA)
Secure Gateway Appliance (SGA)
2. Do you currently use Prism Central today and does it run in the same Prism Element cluster where the Frame workloads will run?
Why ask? Prism Central is required for Frame workloads for on premises Frame deployments
Advanced Discovery
1. How do you optimize your image?
Why ask? Image optimization is crucial in all EUC environments. The host density and the user experience is increased by optimizing the VM using the tools provided by Citrix, VMware or vendor independent.
Citrix: https://support.citrix.com/article/CTX224676
VMware: https://flings.vmware.com/vmware-os-optimization-tool
2. What is your Antivirus Strategy?
Why ask? The right AV solution can also have a massive impact on user experience and host density. If not done correctly all file operations lead to file scans, which increase CPU and IO on the host.