The workload characteristic of virtual desktop infrastructure (VDI) operating environments - multiple users utilising a wide variety of applications at irregular intervals - can make significant demands on the overall solution.
For example, simultaneous logins by users (login storms) or a cluster of application launches can bring about sharp spikes in I/O activity that the storage system can’t keep up with, resulting in slow response times and diminished productivity from users.
Indeed, an Enterprise Strategy Group (ESG) survey1 underscored the significance of such problems, with 38% of its respondents selecting poor performance as a major concern when implementing a desktop virtualisation solution.
Addressing this challenge is made more difficult by the fact that a company’s VDI environment continually changes as its business needs naturally evolve. As new departments or branch offices are brought into the infrastructure, the number of users increases and the mix of user profiles changes. New servers, hypervisors, and storage systems are periodically deployed, as a result.
IT administrators face an ongoing cycle of provisioning new desktops and reconfiguring the desktop pool in order to rebalance available resources and provide reasonable and predictable performance. Such VDI configuration is often a trial-and-error process because it’s difficult to characterise performance across the different layers of the VDI (storage hardware, hypervisors, server resources, I/O controllers, networking and client devices).
Unable to accurately gauge end-to-end performance or to calibrate the configuration against requirements, and lacking insight into how configuration variables precisely impact VDI performance, IT departments often resort to over-provisioning to preclude performance issues. This adds unnecessary cost and diminishes the VDI’s return on investment (ROI).
Solution: Integrated Storage and Compute for Performance
Historically, the separation of VDI and storage has always presented a difficult integration challenge that hindered successful VDI deployment and optimisation. But now, due to the convergence of today’s leading server and blade platforms with Nexenta® VSA for VMware® Horizon View™ (NexentaConnect), that separation has been eliminated. NexentaConnect (formerly NV4V) combines compute, network and storage into a single platform to greatly simplify the process of setting up a desktop virtualisation solution.
The NexentaConnect Deployment Manager utilises user-defined desktop characteristics for the desktop pool, and its auto discovery of internal storage within the VMware® vSphere hosts enables NexentaConnect to take advantage of any SSDs that are present. NexentaConnect then coordinates the many operations that must take place with VMware vCenter™, vSphere and Horizon View Connection Server. The result is a fully provisioned Horizon View Desktop pool with integrated storage.
What’s more, the benefits of NexentaConnect extend beyond initial VDI deployment; the NexentaConnect Performance Manager and built-in host-client tools provide real-time analytics of the virtual desktop environment. VDI environment expansion is simplified through the Configuration Manager, and using the analytics from the Performance Manager, NexentaConnect can recommend and configure storage.
Figure 1. NexentaConnect abstracts local storage as a virtual storage appliance
- Flexible, scalable storage architecture utilising standard x86 hardware or virtualisation host
- Installs on same hardware that contains VDI VMs, boosting storage performance for all VDI machines
- Communicates with VMware vSphere and Horizon View to deploy a customised storage platform with virtual desktops
- Integrated performance and benchmarking tools to assess steady state and boot storms
- ZFS file system technology provides accelerated write performance, greater data integrity, inline data deduplication and compression, fast snapshots and cloning.
- Deploys as a VSA or directly on bare-metal configurations
- Lowers overall costs of deploying and managing a virtual desktop solution
- Implementation in hours with integrated tuning
NextentaConnect Delivers Higher VDI Performance
Desktop deployments are optimally validated through the use of steady state performance testing, with tools employing simulated user behaviour that closely resembles real-world workloads. Using the industry-standard VDI testing tool Login VSI 3.6, the gains seen with Nexenta VSA for VMware Horizon View over traditional VDI deployments are dramatic:
- Higher throughput to SAN
- ZFS compression and streaming writes deliver more payload more effectively to IOPS-bound spindles.
- Benchmark results indicate up to 2× write/8.5× read throughput improvement using NexentaConnect.
- Higher IOPS delivered
- More available IOPS during high SAN contention
- Up to 1.5× write/4.4× read IOPS improvement delivered using NexentaConnect.
- Lower latency realised with NexentaConnect
- Up to 77% write/82% read latency reduction during extreme operations
- Up to 81% write/53% read latency reduction during normal operations
- Higher density realised with NexentaConnect
- Up to 72% higher VSImax score with Login VSI during extreme operations Table 1. NexentaConnect Abstracts Local Storage as a Virtual Storage Appliance (VSA)
*Test results obtained using Cisco UCS C240 M3. According to the Login VSI 3.6 test results, the maximum virtual desktop density for a single Cisco UCS B230 M2 with Nexenta VSA for Horizon View is 196 virtual desktops.
NV4V leverages the cache capabilities of ZFS to place a cache wedge between the virtual machines and the storage. As the VSA sits directly on the hypervisor and uses system RAM as its cache, not only are the blocks retrieved almost immediately, they do not leave the system as they are delivered to the virtual machine, acting as an accelerator for the VMs and offloading the I/O workload from the SAN.
More importantly, the tightly integrated appliances are automatically optimised specifically for VDI workloads and management. This also means that the full software stack can be deployed to any in-house servers and storage arrays.
Seagate® Enterprise Performance 10K HDD for VDI Solutions: IOPS, Efficiency, Reliability Are Key
VDI solutions place enormous demands on the IOPS performance of their hard disk drives (HDD). Not only must these HDDs deliver exceptional read and write speeds (in both random and sequential modes), they must also provide enterprise-class reliability to withstand the rigorous usage patterns of typical VDI environments.
On-premise VDI solutions are frequently deployed in branch offices and other remote sites without the physical space, power and cooling capabilities found in centralised data centres. Optimal VDI deployments in these smaller facilities utilise blade servers with small form factor HDDs that combine high capacity with low energy consumption (and thus reduced cooling requirements).
The Seagate Enterprise Performance 10K HDD provides a blend of performance, efficiency and reliability that is ideally suited to VDI storage deployments. Seagate Enterprise Performance 10K HDD drives deliver:
- Up to 30% faster sequential performance and up to 13% higher random performance than competitive drive offerings
- Up to 100% more data in half the rack space than even the highest-capacity 3.5-inch, 15K-RPM HDDs
- Best-in-class random read access times at 295 IOPS
- Improved storage efficiency with performance efficiency index of 0.0038 watts/GB
- 70% smaller footprint and double the capacity compared with legacy 3.5-inch form factor drives
- T10-compliant Seagate PowerChoice™ technology to tailor systems for optimal power utilisation
1 ESG Research Report, Desktop Virtualization Market Evolution, February 2013.