In my last article, I described what VMware ESX Server is and what it can do for you. All of that is well and good, but what if you already know what virtualization is?
Some of you out there may already be using another virtualization product and may be wondering if you should “make the switch.”
What is the difference between ESX Server and VMware’s other products?
How does Microsoft’s virtualization options compare to VMware’s?
Are there any other virtualization software options out there?
These are the questions I will attempt to answer in this article. So read on.
VMware ESX Server vs. VMware Server
These two products share very similar names, and even similar uses. So what is the difference between them?
One important distinction is that VMware Server (formally GSX Server) is a free product.ESX Server on the other hand can cost large amounts of money, into the thousands, for a full deployment.
The price difference however, should not be the sole factor that determines the decision in either direction. The fact of the matter is that the VMware Server is a great product, but it is not necessarily meant to be used by larger enterprises.
The ESX product is designed from the ground up for performance. This means that ESX Server can safely host more virtual machines on the same hardware than VMware Server can. The main reason for this brings us to the next difference between the two products.
The way that most virtualization clients work is to be installed on top of the native operating system on the physical machine. On the other hand, ESX Server does not need to be installed on any native operating system. It runs on its own kernel which is installed directly on the hardware of the physical machine.
Essentially ESX Server is its own operating system. This keeps the resource overhead much lower in ESX Server than in VMware Server, and therefore keeps the performance significantly higher.
Another important distinction between these two products is the fact that the way they store information about their virtual machines is inherently different. Since ESX server runs without an operating system, it uses its own file system to store virtual machine information on the hard disk.
Server has to use whatever file system its host OS uses. This can be another slight hindrance to performance, as normal OS file systems aren’t really specialized to handle saving virtual machine information. Of course, these are only some of the differences in the product.
ESX Server also has some limitations that VMware Server doesn’t have. For instance, ESX Server can only run hardware that it has drivers for. Whereas the other product can run whatever hardware the underlying OS can run.
In the end, the deciding factor here should be how serious your need for virtualization is, and whether or not you can afford the extra cost that comes with the extra performance from ESX.
VMware ESX Server vs. Windows Server Virtualization
Windows Server 2008 has been in the works for a long time now. One of its much-touted features is Windows Server Virtualization (WSV). Where VMware Server is a product that is clearly meant for different uses than ESX Server, WSV is meant to be a direct competitor to ESX server and other enterprise level products.
However, the differences between these products are more difficult to ascertain because WSV is not yet available. One difference that is important to highlight is that WSV is a product that is included within Windows Server 2008. Therefore, it will run inside of that operating system.
It can also be said that since ESX Server is a proven product that has been on the market for a while, the support for add-ins and additional features is going to be greater in ESX, at least for a while.
Also, it is unknown whether there will be separate licensing for Windows 2008 and WSV. This means that we can’t know for sure whether it will cost money to get access to WSV beyond what it costs to get a license for Windows 2008.
Of course, if it turns out that WSV is “free” and Windows 2008 is cheaper than ESX Server, it may put Microsoft’s product in a very interesting position to start narrowing the gap between the two products right away. There is no real way to know until the product is officially released, however.
What Else is Out There?
There are many other products on the market right now which compete with ESX Server. So if you’re interested in finding our more, check out this Wikipedia article: Comparison of Virtual Machines.
It’s pretty clear that right now VMware ESX Server is one of the most popular, most well supported, and feature-rich virtualization products available. Armed with the knowledge you now have, you can decide if it’s time your company to switch over.
What is your favorite feature or virtualization product? Let us know in the comments!