Today, it is a known fact that desktop virtualisation architectures touch many, if not all components and layers of an IT infrastructure. Thereby, we are confronted with many challenges and issues due to the requirement of creating a harmonized infrastructure, where all components interact well with each other to ensure the best user experience by also meeting IT and business objectives. This was not a mandate in the traditional IT model, where we did work in silos.
Therefore, it is crucial to understand the big picture, but also the involved layers, their dependencies, and interactions to successfully design and deploy desktop virtualisation. Dan Feller - Citrix's specialist recently discussed in his blog around Designing your desktop virtualisation architecture the key layers for any desktop virtualisation implementation starting from the top since it will guide the lower layers:
- User Layer
- Access Layer
- Desktop Layer
- Control Layer
- Hardware Layer
Once you went through the top layers and made your design decisions, you will get to the hardware layer. Since you already did your homework of gathering all relevant information, determining a suitable hardware platform will be much easier. Usually, a hardware platform for desktop virtualisation consists of several components and mostly from multiple different vendors, where the interaction can be challenge. Not only from a configuration perspective, but also from a maintenance and support perspective. This is why it is crucial to invest into a platform that provides a harmonized solution to deliver the architecture for desktop virtualisation with all benefits from a user point of view – user experience, mobile work styles – and IT relevant aspects such as scalability, modular architecture, cost savings, etc. Cisco announced yesterday their Cisco Desktop Virtualisation Solutions, which is based on the Cisco Unified Data Center. The beauty of it is that several primary industry partner solutions are part of an architecture to deliver an open, end-to-end, and service-optimized infrastructure for desktop virtualisation architectures.
Cisco provides with their Desktop Virtualisation Solutions four architecture models supporting any XenDesktop deployment – from small scale with hundreds of desktops up to large scale with thousands of desktops.
This architecture model is probably in its simplest form and delivers a platform for non-persistent desktops in a small scale deployment, where a SAN infrastructure is not necessarily available and reduces thereby the costs associated with virtual desktops. The key for this architecture is that local storage on the servers is being leveraged in form of high-speed, low latency flash-memory based storage (SSD and PCI Express flash-memory modules) on the Cisco UCS servers. Therefore, the IOPS are kept local to the server providing a good user experience.
The Simplified Architecture provides a simpler network architecture with shared storage connected directly to Cisco UCS Fabric Interconnects. The key aspect for this architecture is that it provides a cost efficient entry point, where shared storage is lacking and/or SAN infrastructure being considered and growing. The architecture is based on virtualized storage with appliances such as Atlantis Computing, Nimble Storage, and EMC. This is ideal for medium scale environments, where multiple FlexCast delivery methods are being considered and the environment is expected to grow.
This architecture is probably a very common implementation type and is targeted at medium to large scale environments with thousands of virtual desktops. It is architected around shared storage infrastructure and a resilient and scalable designed switched/shared fabric-based approach. A single architecture can serve up several thousands of virtual desktops and provides the flexibility and scalability needed to do so. Due to the scale and a single architecture approach, it supports a multi-site deployment as well by leveraging all Cisco UCS benefits such as UCS Manager and UCS Central.
This architecture is the most comprehensive and definitely designed for large scale deployments, where a modular architecture is a must-have that is highly scalable ensuring rapid deployments of thousands of desktops, simple to manage, and has a converged support model. Besides large organizations, this is an architecture well-suited for service providers requiring capacity, but also options to grow the environment as needed. The packaged solution definitely simplifies this and supports a block-based scale out.
Sounds all good, maybe too good, right? Actually it is. As mentioned above, once you gathered all information you need to determine the required hardware platform, you can pick from these solutions that serves you best for your XenDesktop implementation for desktop virtualisation. But it is always best to see how these have worked in real-world environments, which you can check in the recent Cisco webcast “Customer Insights: Desktop Virtualisation on Your Terms” available here.
Source: Citrix's Blog