Nexenta virtual storage appliance for virtual desktops

Nexenta recently launched NexentaVSA for View that is designed to handle the storage demands made by desktop workloads that are executing in a VMware View-based, server-based environment. The company points out that virtual desktops use storage differently than server-based workloads do, so they need to be configured differently.

How Nexenta describes Nexenta VSA for View

NexentaVSA for VDI is a purpose built storage appliance that provides advanced features and functionality suited to handle the demands of a virtual desktop environment. NV4VDI improves desktop / storage performance by providing better IOPS, latency, and boot storm response. NV4VDI can scale to thousands of machines without changing design or incurring cost overruns, thereby lowering the overall cost of deploying and managing a desktop.

NexentaVSA for View provides comprehensive functionality, including in-line data deduplication and in-line compression, flexible back-up and restore, unlimited snapshots, metadata acceleration, and uniform IOPS at any scale.

Snapshot analysis

Nexenta is one of several storage virtualization suppliers that are offering products designed to increase the overall performance and reliablity of virtual desktop environments. Other suppliers of products that address the same issues include companies such as NetApp, EMC, IBM, HP, Hitachi Data and a few others.

Why is this necessary? Well, there are many differences in how server-centric and desktop workloads use storage. Just connecting the host server to a virtualized storage environment may or may not perform well. Some of the differences follow:

• Desktop systems typically are provisioned with low-cost storage devices. These devices perform well enough to address how they're going to be used. Server workloads typically are supported by higher-cost, higher performance storage devices.
• Server file systems are optimized to use big blocks of data to maximize caching and minimize I/O operations because server workloads traditional do more processing on each unit of storage. Desktop file systems are optimized to use small blocks of storage and assume that only a small amount of processing will be done on each unit of data.
• Server workloads typically transfer larger amounts of data into and out of storage in every operation.  Desktop workloads transfer many more small amounts of data in the same time period. The storage caching mechanisms must be adjusted so that desktop workloads perform well.  This means addressing the requirement of many more small I/O operations.
• Servers don't go off and online all at the same time so there aren't "storms" of storage requests at the beginning and ending of each staff shift. Desktop workloads tend to come online at the beginning of each shift and go off line at the end of the shift. Once again, if the storage caching mechanism is configured for server-centric workloads, desktop workloads will perform poorly during the "storage storms."
• Server-oriented management tools have different expectations of storage and different requirements. Storage is a shared resource on servers and this requires fine grain control of who can use files and applications. Desktop environments are typically support a single user's applications and data.
  
  • Server environments typically keep one copy of applications and shared data.
  • Each desktop environment expects to have its own copy of the operating system, applications, application frameworks, database engine, databases.

Nexenta says that it has addressed all of these requirements and has make it possible for VDI environments to perform well and be managed by VMware's Horizon View management environment.  While this is likey to make VMware View users happy, VMware is not the only VDI game in town. It is not clear at this moment if users of Citrix or Open Source desktop virtualization environments would see similar benefit from NexentaVSA.

Furthermore, encapsulating complete desktop environments and moving that image to servers is not the only form of desktop virtualization. Some approaches to virtual desktops are based on access or application virtualization rather than relying so heavily on virtual processing.

Nexenta is offering some interesting technology that might be of great help if your organization's virtual desktop program is based upon VMware. It would be worth examination if that is what your environment is using.  If not, then the products being offered by others would be worth considering.