What you need to know about Nutanix announcement extending support to Citrix XenServer.

During Citrix Synergy 2016, Nutanix announced the support for XenDesktop with InstantOn VDI, offering customers “a full stack, end-to-end VDI solution that delivers an enterprise level experience at an affordable price point”, a collaboration that led to this latest Nutanix announcement, extending support for Citrix XenServer as a deployment option for pre-configured hyper-converged infrastructure (HCI).

This solution makes it possible for Nutanix customers to leverage XenServer for the simple, secure deployment of Citrix application and desktop virtualization along with rich functionality and enhanced end-user experience, without additional vTax hypervisor costs.

The combined Nutanix HCI and Citrix XenServer stack offers myriad end-user and IT admin benefits, including:

End-user graphical experience

XenServer first introduced enhanced 3D graphics virtualization with NVIDIA GRID vGPU in 2013, allowing end-user applications and desktops to benefit from direct GPU access. With support for enhanced graphics through NVIDIA’s M60 chipset on Nutanix HCI, customers can experience a graphically rich user experience across all common use cases, from the more demanding CAD & CAM applications, through to productivity applications, such as Microsoft Office and internet browsers, all of which serves to lower the per-VM and, subsequently, per-host CPU utilization.

VM CPU usage whilst presenting with PowerPoint with, and without a GPU

The above graphic highlights how a VM’s CPU utilization, delivering a Microsoft PowerPoint presentation can differ when a GPU is used. As more virtualized application and desktop users per-host leverage GPUs, not only do they benefit from a smooth graphical experience, but the IT team benefits from being able to scale hosts higher with a greater number of VMs. Enhanced graphics support is not limited to Windows either, with NVIDIA GRID vGPU support for Linux workloads. Citrix support for Linux workloads extends to HDX and XenDesktop optimizations and support.

Revolutionary security

XenServer Direct Inspect APIs are revolutionary in securing virtualization infrastructures against malicious datacenter activity. Leveraging hypervisor memory introspection, security vendors can integrate with XenServer to offer customers “better than physical” workload protection, a market-first for the hypervisor that uses a host-level security appliance with no in-guest VM agents for zero-day protection.

Infrastructure management & support

XenApp/XenDesktop customers typically use one of a couple of methods for managing their app & desktop VM disks & images: Provisioning Server (PVS) or Machine Creation Services (MCS). Support for XenServer with MCS for Citrix workloads, enables simple desktop VM disk management while consuming minimal storage capacity. Add to this XenServer’s In-Memory Read-Cache, which integrates with MCS as a host-side cache, and customers can see whole-host VM boot times improve by as much as 300%. With support for up to 255 disks per-VM, XenServer is the best option when considering App Disks. Customers wanting PVS support are also able to deploy Citrix workloads on Nutanix HCI with XenServer support.

While there are, unfortunately, times when customers need to engage with Support, only XenServer’s Health Check with Citrix Insight Services (CIS) integration equips Citrix and customer support teams with all relevant data from the hypervisor through to the application and desktop layers, simplifying and expediting the support process. For its part, Health Check automates the uploads of infrastructure reports, CIS analyzes and then reports back to XenServer on potential infrastructure issues, allowing Support to take pro-active action.

Citrix Insight Services

A challenge that larger customers have faced in the past is around in-guest driver and agent management. How do you upgrade hundreds or thousands of VMs when there are updates? Starting in XenServer 7, the XenTools, which contain both an agent used for reporting on VM state & performance, as well as the I/O (para-virtualized, or PV) drivers used to optimize performance, can now both be automatically updated. This frees infrastructure admins from this once onerous task.

As seen from the process graphic below, new VMs can automatically receive the initial PV driver installation, and all future updates from Microsoft Windows Update, as per any corporate policies for updating Windows VMs (such as via Microsoft Active Directory group policies). The automatically installed lite-agent enables basic management, but with a one-time installation of XenTools, the full management agent is installed, and then kept up-to-date via a Citrix run service.

PV driver installation & update process

Who uses XenServer and why should Nutanix customers consider it?

For many years, the XenServer product group has put a strategic emphasis on hypervisor optimizations for Citrix infrastructures. Do you remember the XenApp memory optimization in XenCenter, which allowed for VM shadow memory multiplier modification, and subsequently increased XenApp user sessions scalability? It’s an old, but great example of XenServer innovation helping to improve customer TCO. But the work didn’t stop there, with more recent innovations focused on virtual graphics, host-caching, driver management and, of course, security.

From a product scalability perspective, XenServer scales to run more VMs/host than any customer use cases; with Engineering & QA testing to over 1000 VMs/host, and with Login VSI scores demonstrating over 500 VMs/host for medium workloads, however the majority of customers choose to deploy no more than few hundred VMs/host, a result of hardware platform and individual VM sizing choices.

Existing customers come from all business verticals, including manufacturing, finance, education and healthcare, with some, for example, using XenServer as the platform from which to design race cars, aircraft and things that go even higher and faster. Customer deployment sizes can vary, ranging from sub-1000 seat accounts, to larger 10,000-seat global organizations (check out David Cottingham’s blog post for a deeper insight into XenServer usage below XenDesktop).

You might now be wondering what the customer cost will be when choosing to deploy XenServer for Citrix XenApp or XenDesktop solutions. Well, XenServer is included with XenApp/XenDesktop licensing, meaning that regardless of which XenApp or XenDesktop edition you purchase, there are neither additional license, nor software maintenance (SWM) support costs.

What you gain, however, is access to the entire XenServer feature set of this highly performing and scalable hypervisor, better together with XenApp and XenDesktop, and now with Nutanix HCI.

What next?

Initial Nutanix HCI support for XenServer is available via a technical preview for existing customers, with full support coming soon. If you would like to participate and/or discuss XenServer capabilities or support with Nutanix, please register your interest here, and someone will contact you.

Expect to see and hear more on this from both Nutanix and Citrix over coming months, but in the mean time, further information on XenServer can be found on the Citrix website here and from the XenServer 7 launch blog here.