Making VDI invisible.

An exciting day! Today Citrix and Nutanix announced Nutanix Acropolis to be Citrix Ready. Not just for XenApp and XenDesktop, but also for Sharefile and Netscaler.

Nutanix Citrix fabric

In this post I want to focus on the impact of this for desktop virtualisation.

The moment that the modern VDI concept was incepted almost a decade ago, it immediately became one of the most complex datacenter beasts to design, build, scale and maintain.

DV stack

To pull it off you needed to build an entire stack, consisting of the basic compute hardware, storage and a storage fabric, networking, a hypervisor, image provisioning, application management, profile management, environment management, endpoint control etc etc.

Expectation? Easier desktop management, lower costs, more flexibility.

Reality? Increased complexity & high costs.

When I was still at Citrix, one of my biggest frustrations with PoC’s and production deployments was that while Citrix has the top technology in the VDI space with XenApp and XenDesktop, it was often devaluated by poor physical infrastructure below it. Sometimes something we could guide or avoid (if it was a knowledge or configuration issue), but most of the time it was hard to control for Citrix what was being put underneath it.

The situation improved over time by the installation processes of XenApp and XenDesktop being simplified, new technology like MCS and Director added to the product to simplify provisioning and monitoring, but a couple of fundamental things remained to become either performance or complexity bottlenecks: the storage infra (often SAN based) and the hypervisor, most of the time VMware ESX with vCenter or Microsoft Hyper-V with SCVMM.

When I left Citrix in May 2014, I joined Nutanix while still being in their ACT 1: making storage invisible. This alone already was a huge thing to remove complexity from VDI, or any other workload that was suffering from aging legacy SAN based infra.

Many current Nutanix customers turned to us to help them solve common performance and scalability issues in their VDI deployments, both Citrix and VMware based, by simply removing the complicated storage fabric and transforming everything into software.

When we progressed into ACT 2 at our recent .NEXT conference in Miami in June, Nutanix released it’s own Acropolis hypervisor to the world, with the purpose of making infrastructure invisible. The Acropolis hypervisor is a fully integrated part of the software stack of a Nutanix node, leveraging the Distributed Storage Fabric for it’s storage needs. Graphical management is provided through Prism, and for automation you can use some very powerful REST API’s. And all of this is automatically fully distributed across all nodes in the cluster.

So I feel great pride in the fact that today Citrix announced it’s official support for Acropolis as a platform to run XenDesktop on. You can read the full press release here and the Citrix Ready information for Acropolis in the Citrix Ready Marketplace.

This means yet another step in simplifying VDI, and it’s a significant step at that. No longer is an expensive, and complex hypervisor platform needed to deploy virtual desktops. No longer does the admin need worry about deploying a hypervisor, but also, for example, create a fully resilient VMware vCenter or SCVMM setup so XenDesktop’s Controllers can talk to the hypervisor.


To show you how complex for example setting up a resilient vCenter is, I’ll quote the procedure (courtesy of Lukas Lundell, posted in this recent article):

  1. Provision two Windows Platform Services Controllers (PSC), using HCL supported operating systems.

  2. Run Windows update and fully patch both PSC VMs.

  3. Join the PSC VMs to your Windows domain, and reboot.

  4. Mount the vCenter ISO on PSC #1 and run the installer, deploying an external PSC. Join an existing SSO domain, or start a new SSO domain depending on your requirements.

  5. Mount the vCenter ISO on PSC #2 and run the installer, joining the second PSC to the first PSC/SSO domain.

  6. Manually configure your third party load balancer (F5, NetScaler, etc.) per VMware instructions for HA PSCs.

  7. Provision one vCenter Windows Server VM on a supported HCL supported operating system.

  8. Run Windows update and fully patch the vCenter VM.

  9. Install the Desktop Experience/Flash player on the vCenter VM.

  10. Run Windows update again to patch Flash/desktop experience.

  11. Provision a pair of HCL-listed clustered SQL servers for database high availability. Do not use SQL AlwaysOn Availability groups, as this is not supported. Deploy a traditional SQL cluster for HA.

  12. Manually create vCenter databases in SQL.

  13. Install the ODBC driver on the vCenter server, using HCL supported SQL version.

  14. Create vCenter service account.

  15. Create ODBC connection to SQL database.

  16. Mount the vCenter ISO on the vCenter VM and start the installation process.

  17. Deploy vCenter, using the HA PSCs and HA SQL servers.

  18. After vCenter is installed, add ESXi hosts to vCenter.

  19. Review VUM SQL HCL, and create a VUM database on a supported SQL version.

  20. Create VUM database in SQL.

  21. Create VUM ODBC connector on vCenter server.

  22. Install VUM on vCenter server, and configure downloads/schedule.

  23. Scan ESXi hosts for update and patch as needed.

  24. Use Derek Seaman’s SSL toolkit and VMware Certificate manager and manually create/deploy SSL certificates for PSCs, vCenter, VUM and ESXi hosts. Go Team Derek!

  25. Update load balancer SSL certificates to support high availability.

  26. Configure VMware HA to protect PSCs, SQL, and vCenter VMs.

  27. Configure NTP on all ESXi hosts, or configure host profiles and deploy to all ESXi hosts.

  28. Install Flash Player on all servers/clients used to manage the environment via the web client.

  29. Install the C# vSphere client on servers/clients as needed to manage the environment.

  30. Record all passwords/service account details in enterprise password management solution.

It’s 30 steps with a magnitude of clicks involved to set it all up, just to enable XenDesktop to deliver a virtual desktop. A setup of the SCVMM and Hyper-V combo also contains many steps to get fully resilient. Even XenServer doesn’t get rid of this problem. With it’s pool type setup and having a Pool Master, you somehow need to make the point of contact between the broker and the xapi interface highly available, and you still don’t get rid of the hypervisor management itself.

With Acropolis, this whole proces is obsolete as the hypervisor management layer is already there when a node is turned on for the very first time, and it’s fully distributed among the cluster with no single point of failure.

By selecting Acropolis as your platform, you immediately make half the needed VDI stack invisible.

To be clear and open though, XenDesktop support for Acropolis is not gonna be fully featured right from the start. We have a roadmap defined for adding features and we (Nutanix AND Citrix) will be improving the technology as we go along. But the intention for us is to contribute yet again into simplifying VDI, and make all that complexity disappear.

Stay tuned for more technical posts and in the mean time sign up for this webinar on the 22nd of september for more in depth information:

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