Virtual desktop Storage Basics: overcome restrictions and bottlenecks (1)

Virtual desktops simplify management, but need to be properly planned to eliminate storage performance bottlenecks, ensure performance and meet growth needs. The storage subsystem can simplify VDI deployment, but without best practices, its costs will soar. In the first part of the four articles in this series, I will help you understand the storage restrictions brought about by virtual desktops and how to overcome bottlenecks.

Over the years, it has been proved that desktop virtualization is a reliable technology that can help enterprises manage and control multiple terminals in a new way. This is not possible for old desktops and laptops. Application virtualization can distribute key applications running on servers to multiple users.

In the VDI architecture, the entire desktop is installed on the server and provided to the simple terminal through the LAN. It is also limited by all client or server computing modes, such as server and network damage. Therefore, enterprises trying this new technology also need to understand the bottlenecks that all virtual desktops may bring.

Storage and desktop virtualization restrictions

On the surface, new technologies such as VDI are very good. VMware View or Citrix XenDesktop allows you to deliver a complete desktop in a central data center to simple terminal devices. Administrators can perform full desktop management, fast distribution, software installation restrictions, and patch upgrade for operating systems and applications. Theoretically, an administrator can manage hundreds or even thousands of desktops without leaving the data center.

The reality is not so beautiful. Desktop virtualization follows the client or server mode and is subject to the same restrictions. For example, a user session is disconnected due to network or server issues, making the terminal device unavailable, resulting in production interruption.

In terms of storage capacity, potential problems are even more prominent. Assume that an enterprise with 1000 employees reserves 50 GB space for each desktop, which means that 50 TB of enterprise-level SAN storage capacity needs to be added to the data center. The actual capacity usage is more efficient than this, but the potential storage needs cannot be ignored.

In addition to the huge storage space requirements, you also need to pay attention to various performance issues, such as storage access. Different from the storage capabilities required by server-based applications, desktop systems usually require more random storage access.

For example, a user may be downloading the audio while another user is accessing the video. Another user is processing the electronic form while another user is accessing a file. As multiple users generate read/write access to the storage in a variety of unpredictable ways, the storage subsystem is easily overloaded without good planning.

There is also a pressure on multiple users to access storage devices at the same time, which is called "startup Storm ".

"Everyone starts up and accesses their respective virtual desktops at on Monday," said Ray Lucchesi, Chairman and founder of Silverton Consulting, "This behavior will impose a huge performance burden on the storage system."

This phenomenon is also known as "resource Storm": a large number of users start to enable storage read/write tasks at the same time within the working day, such as watching a video clip to eliminate virus infection ).

Of course, some potential problems may not only occur on storage, but users' behaviors may easily exceed the computing power of the most powerful server. For example, anti-malware greatly increases the requirement of virtual desktops for CPU and storage read/write.

"Open Resource Manager, observe what services are running in your PC, and track the consumption of CPU, memory, and disk resources," said Keith Norbie, vice president of sales at Nexus Information Systems, "In this way, we can know what occupies resources."

These requirements will be converted to the status of virtual desktops running on the server. When you consider the effects of hundreds or thousands of virtual desktops, you can easily see the impact of a small POC test.

The accumulation of resource requirements may cause large-scale problems. If ignored, it may lead to poor performance, project failures, or extra budget servers, storage, and networks, all of which make the ROI of desktop virtualization questionable.