Guest Blog Post (Part 2 of a 3 part series)
By Georges Khairallah, systems engineer, Chino Valley Unified School District
Virtualization has come quite a long way. You can now virtualize your servers, your desktops, your applications, and even your storage. If you understand the general benefits of virtualization, it is hard to not want to virtualize everything. There are, however, some things you need to consider before moving forward, specifically related to K-12 and desktop virtualization.
So let’s look at some factors to consider when rolling out a virtual environment…
Storage:
Storage is going to be key in every implementation. Whether you are starting with one server or 15 servers, you want to make sure to plan your storage correctly. Failure to correctly plan for storage is one of the biggest mistakes that can be made when it comes to desktop virtualization.
At Chino USD. we researched storage carefully (and having used both traditional SAN storage technologies and virtualized storage technologies with thin provisioning), I would recommend the latter option. This approach – virtualized storage technologies with thin provisioning – will require some learning, but it is far easier to implement and manage than traditional storage. Thin provisioning is a storage technology that allows storage to be more efficiently managed- by allocating physical space as needed. Also, by virtualizing your arrays, you can add additional (disks) to your SAN arrays, and get rid of traditional requirements for same-size disks within an array etc. Because the physical disks themselves are not creating volumes, the environment becomes much more flexible to change. Expanding and managing volumes becomes a snap with thin provisioning.
Servers:
Servers are surprisingly one of the easiest things to virtualize. There are tools that allow you to virtualize servers in place, while powered on. (see VMware vCenter converter and VMware converter standalone). Though if possible, I wouldn’t recommend doing a live conversion on your most mission critical servers, but some secondary servers can be converted live with no issues.
In some instances, I have converted a server mid-day, with only three-minutes of downtime. If you can manage to virtualize all your servers, you will have done yourself a favor, because your management time will easily be cut in half.
The key to a successful server conversion is making sure you take the time to correctly plan your infrastructure.
When I initiated our virtualization project at my district, I started by using the free VMware server 1.x product, and placing one to 2 servers on each of those hosts. Initially I did this due to hardware limitations. Though this gave a kick-start to the project, and was a good business case to move forward, I spent quite a lot of time duplicating efforts.
If you are looking at virtualizing your servers, you will be much better off pulling together a business case based on your own environment. VMware’s ROI calculator is a good tool and can be a great resource in this respect. Once you have done your research, make sure you get the hardware required to build out enterprise-grade infrastructure from the outset.
Desktop and Applications:
This is new territory. That said, a lot of school districts are moving to desktop and application virtualization, for good reasons, the first and foremost of which is based on the ROI and TCO. The VMware ROI calculator can also be used when looking at the TCO around a virtual desktop environment.
Just as virtualizing servers requires some overhead, desktop virtualization requires more of the same. The difference however is that in the desktop world, there are more factors to consider.
A couple of items to think about when moving from a physical desktop environment to a virtual desktop environment:
- Shared storage is a must: built-in storage from a server is not enough for two reasons:
- Capacity – running desktop infrastructure, even with the linked-clone technology for VMware View, requires a significant amount of storage.
- The physical number of disks on which the VMware View volumes reside also matters – because the number of IOPS matters. Your mileage may vary depending on what type of disks you are using. See http://www.networkworld.com/reviews/2010/041910-ssd-hard-drives-test.html?page=1 for a traditional vs. SSD performance differences.
- If you opt to keep using current thick clients with desktop virtualization, you will lose out on power savings that can be realized through the use of thin clients, and you will essentially pay double on your OS licenses.
- If you are replacing your thick clients with thin clients, then you will need to account for the added cost of thin clients. However, you will be able to avoid the cost of the OS and other licenses. The upside of this model is that you will truly maximize your ROI by leveraging the energy savings that you can harness from these clients.
Let me now turn to application virtualization. VMware ThinApp allows an application to be packaged in a virtual environment, with its own registry, application settings and sandbox. This allows applications to run on multiple platforms, even if the applications are not specifically designed for these platforms.
An example of this would be a legacy application that only works on Windows XP, which is needed to run on Windows 7. In a school district, this tends to happen a bit more often than we’d like, and having a virtual application that can be moved around across platforms is a lifesaver.
These virtual applications do not use cumbersome complicated installers, but rather can be deployed as a neatly packaged executable (one single file), which can be simply pushed out to workstations and run as a standalone application.
When it comes to application virtualization it is important to note that combining the capabilities of VMware View and ThinApp is the most time efficient way to implement, or make changes on virtual desktops in a very short amount of time.
VMware ThinApp is quite affordable, and can actually be used in your non-virtual environments as well, as a method to distribute applications to your users.
In my next blog – I will look at “Some Key Take-Aways,” when rolling out a virtual environment.
Georges Khairallah is a systems engineer at a large school district in Southern California, with an overall passion for technology.His main focus revolves around directories, virtualization, and systems integration. He stays heavily involved in new technology, and has a special interest in making any admin's life easier and more efficient. You can follow his blog at http://blog.foreignkid.com.
