Paralles Virual Desktop Infrastructure

How would you like to free up at least 50% of your desktop administrators' time? VDI is a complex term for the simple concept of consolidating end-user desktops on a centralized server. VDI uses virtualization technology to create user desktops, and can potentially pair with many other technologies as a part of a complete solution. The benefits to the VDI approach are many, including simplifying patch management and provisioning new applications to users in seconds. When using Virtuozzo Containers for deployment, you gain significant benefits including a much smaller footprint (resulting in a higher density of desktops), the ability to quickly customize desktops including permissions levels, and unbelievably fast provisioning and update management.

Why Consider a VDI Deployment?

VDI is moving the computing from the end-user to a centralized location. This is a dramatic change in any organization. The main benefits of VDI include:

• Centralized software management is much simpler and more cost effective for the IT organization.
• OS and application patches can be done quickly, reliably and managed centrally.
• Increased resource efficiencies- centralizing the processing onto a server ensures that resources are used fully and efficiently. Some desktops may only use a small percentage of processing capability, while others constantly exceed processing capabilities.
• Data security- Data backups can be completed easily and quickly without user interruption. Typically laptop or workstation backups would be done while the end-user was using the system, slowing processing and detracting from the end-user productivity. As a result, many laptops and workstations are only backed up piecemeal, and instigated by the end-user, if at all. The server could also be a highly reliable and redundant configuration with high RAID and SAN configurations to ensure availability and data access.
• Data is secure and is only accessed by the end-user. For example, there have been instances of laptops with highly secure customer or government data that has been lost by employees.
• Creating a desktop for a new user can be done with only a couple of clicks and in less than two minutes.
• Freeing IT staff from many of the mundane and time consuming tasks of managing and maintaining the desktop computing infrastructure. Forrester conducted a survey regarding the time use of IT desktop administrators. VDI eliminates or drastically reduces 80% of the desktop administrator's workload.

Sizing the VDI Environment

Let's examine a sample Windows desktop consolidation project. Pre-consolidation, you have a thousand desktops and laptops, with 2GB of physical memory, dual 1 GHz CPU, average utilization 10%. The VDI server configuration will be a quad core dual 3GHz CPU server, with 8GB of memory available. Let's calculate the consolidation ratio we can expect with Virtuozzo Containers. Since the operating system will serve all of the virtual desktops, we should reserve a significant amount of the 8 gigabytes of memory for the operating system. In this case we reserve 2GB which should be more than adequate. That leaves 6GB to each of the virtual desktops. Each virtualized desktop will be running in separate virtual environment, which has its own memory footprint. Measurements show that it may be anywhere from 30 to 50 megabytes, so let's assume it 40.

So the total footprint of the virtual environment is 340 MB. However, we didn't consider resource sharing. A part of this footprint is coming from the shared libraries (dll), or application images, and will be shared among multiple Containers on the same server, eventually increasing the desktop's memory footprint. Another part is rarely used and may be safely stored in the swap file. Very conservative sharing assumptions will bring the footprint back to the original 300MB (in real life it would be closer to 250MB, but let's stay on a safe side, we don't want our desktops or users to suffer).

Now let's calculate the consolidation ratio. 6GB/300MB give us 20 VM per server, with again, plenty CPU power per desktop. With more memory, we increase the consolidation ratio. 16GB of RAM, with 3GB given to the operating system leaves 13GB for our desktops, or about 43 Containers per server - and still plenty of CPU power for good desktop performance. However if you are running a 32bit OS, you may run out of kernel memory, that's where a 64 bit OS becomes invaluable because of the unlimited memory capabilities.