Posted by Andreas Groth
IBM ATS Europe, Lead
Architect, x86 Virtualization
& Cloud

Given yesterday's launch of the IBM SmartCloud Desktop Infrastructure, I’d like to share some of the key findings and design principles of our recent work that I had the privilege to lead architecturally from our side.

Having worked closely with the VMware team for over 10 years, the increasing interest of our joint customer base in VMware End User Computing technologies does not come as surprise. Customers aim to naturally expand their existing vSphere virtualization platform to cover new use cases including desktop virtualization, utilizing existing skills and management approaches.

The recent advances in VMware View are impressive, whether you look at PCoIP protocol enhancements, added Persona management functionality, the unique software based 3D graphics capability or the recent addition of the View Storage Accelerator functionality. This combined with VMware’s well-articulated long-term vision around Horizon Application Manager, projects like Octopus and Appblast and the excitement generated by the recently announced Wanova acquisition make VMware an all-round outstanding partner in this space.

So what have we been doing?
We’ve set up three VDI solutions in IBM labs in the U.S. and the UK and performed extensive architecture verification and LoginVSI performance tests on different sets of IBM hardware, including IBM Blades and IBM Rack systems.

Figure 1- IBM SmartCloud Desktop Infrastructure

We also tested the recently announced IBM PureFlex Systems, an integrated system that combines compute, storage, networking, virtualization and management into a single infrastructure system and has therefore great potential to become the ideal platform for VDI deployments.

The key design principle of our Reference Architecture is to address the arguably most common practical inhibitor to VDI – storage cost. Our approach allows the radical reduction of shared storage requirements for your VDI deployment by favouring local SSD storage instead of large-scale shared storage arrays for the performance intense I/O operations that occur in most VDI environments.

Figure 2 – IBM SDI Reference Architecture Approach

This approach is primarily based on a stateless or non-persistent relationship between the user and the virtual desktop image so that users can continue operations even in case of a host failure which renders the local storage inaccessible. While you will gain optimal value from the stateless approach it is important to point out that the SmartCloud Desktop Infrastructure will facilitate both stateless and dedicated desktops as shown below.

Figure 3 – Hybrid of Stateless and Dedicated Users in View 5

A key objective for our architectural work was to determine the supported maximum user density (using LoginVSI) for individual workloads in order to create scalable building blocks and sizing models – essentially make sure our approach works, scales and gets you to the best price point.

In order to give comprehensive sizing guidance I also ensured that we investigated specific aspects of VMware View and the user density impact when enabling certain functions including protocol choice, profile management and graphics capability. For a summary of our findings see the table below.

Figure 4 – VSImax Results for VMware View on IBM HS22 (Intel X5690)

We tested VMware View 5 (currently also 5.1) rigorously over a period of over 4 months and measured all relevant performance metrics, including disk IOPS, latency and network utilization for each use case. The attached sample of the data collected for each(!) test demonstrates the level of detail we adhered to.

Figure 5 – IOPS Sample for Linked Clone DataStore + Performance Data Sample

A recent test series on the new IBM x3650M4 using the Intel E5-2670 processors achieved an impressive density of 164 medium users connected with PCoIP (without any optimization), an increase of over 30% compared to the previous platform!

Figure 6 – VSImax "Medium with Flash" on IBM x3650M4

VMware View coped very well even with this user density, image refresh operations were quick and latency on the local SSD drives never exceeded 4 milliseconds, well below the tolerated thresholds.

Throughout the process we worked closely with the VMware End User Computing team in order to validate our findings and to meet our goal to create scalable VDI building blocks based on IBM hardware (POC system, 300, 450, 1500 and 10 000 users).

Figure 7 – High Level Overview of IBM SDI Building Blocks

Customers value our ability to provide choice rather than a “one-size-fits-all” approach, our leading-edge hardware platforms like IBM PureSystems, combined with IBM’s longstanding expertise in providing implementation services using methodologies and tools developed through real-world client implementations and in that spirit we aim to be “partner of choice” for desktop virtualization.

All I can add is that I am genuinely looking forward to a close and successful relationship with VMware in the desktop virtualization market.

More details and future articles on the IBM SDI RA and VMware View can be found on my personal blog here: http://www.virtualizationmatrix.com/posts/