With x86 server virtualization maturing and competitors to VMware becoming stronger, I figured it was time to talk with some real-world users of server-slicing technology beyond VMware.
This week, I’m focusing on Xen. This newsletter and the next will include an edited transcript of a talk I had a while back with Jim Klein, director of information services and technology for the Saugus Union School District in California.
The district’s IT shop is a staunch supporter – and user – of open source. It has been running Red Hat for years and last year it brought in the open source Zimbra collaboration suite to handle e-mail and calendaring district-wide. It also began running the open source Xen hypervisor in production last year. Check out Klein’s blog and scroll through to read some interesting entries on Xen, Red Hat, VMware and virtualization in general.
But first, here is my talk with Klein about how the district brought in Xen. In the next newsletter, our talk will focus in more detail about the district’s Xen deployment:
When did you start thinking about virtualizing your x86 systems?
What we ran up against, and I imagine this happens often in IT departments, is we had gotten to a point where we just had lots of servers and our infrastructure was starting to age a little bit and it was time to do some refreshing. This was in mid or late 2005. Virtualization was the up-and-coming thing. It made a lot of sense to us because we wanted our infrastructure to be a little bit more agile, and then trim down on the number of raw boxes we had in our racks to make it a little more manageable.
What were the first steps?
We looked at hardware and it seemed obvious that blades are a natural fit for a virtualized environment because they are based on a utility style model. We decided to go with an HP BladeSystem and the next thing we did was try to figure out, “Well, OK, how are we going to virtualize this thing?”
Had you tested out any virtualization software before this?
We knew the basics; we had used some VMware and some Microsoft Virtual Server, but just playing around with them, nothing serious. We did know that we needed redundant hardware because if you lose something in a virtualized environment you lose a lot more than just a single server. We built the environment with a massive amount of redundancy from the beginning. Then we started looking at our software options. We knew that Xen was out there.
Did you decide on Xen right away?
Xen was on the bleeding edge, so we actually were more focused on VMware. It was more well known and it seemed really safe. But the cost of the [VMware] software package was as much as the BladeSystem and the storage array combined -- $40,000. The other problem we had with VMware was the performance hit you take. Typically your I/O performance gets about a 15%-20% hit with VMware vs. Xen, which is only around 2%. So we were looking back and forth and Xen was on the bleeding edge and we knew what its performance capabilities were, but we felt a little safer with VMware. But when we saw how much VMware was going to cost, we started looking at Xen very seriously.
Were you looking at XenSource or Virtual Iron, which both sell commercial products on top of Xen?
We actually started looking at Red Hat because we’re a Red Hat shop and we knew Red Hat was going down that path. What we ended up doing was in early 2006 we grabbed the latest version of Fedora, which had some preview release versions of Xen and started experimenting with that.
Were you getting any pushback from people saying that VMware was a better bet?
Not really and part of that is because we are a proven open source shop. We’ve been using open source for a very long time and it has proven extremely effective for us, so we don’t get that kind of pushback anymore when we want to experiment with an open source product. Everybody knows that it works and that it’s not only cost effective, but also offers, in many cases, more flexibility and functionality. So whenever we see an open source opportunity we have the tendency to jump on it and see how it works. Xen, with all its support, seemed a safe bet.