XenServer, VMWare, and making the case for the correct use of open formats

Posted on October 1st, 2010

Here at SevenL, as many of you know, we are HUGE proponents of Open Source; for many reasons. Aside from the fact that most FOSS projects are free by their very nature, in my mind particularly, open source just makes sense. And I’ll give you a good example as to how and why.

If you have a VPS with us, you know that we run on VMWare ESX, and once upon a time, we also ran all our VPSes on Open Source Xen. Well, let me let you all in on a little secret….work here has begun on consolidating all our legacy Xen VPSes and more recent VMWare VPSes onto a single platform: Citrix XenServer.

Why XenServer? Well, I have to take a bit of credit for that. I have had some very positive experiences with it over ESX or any other enterprise virtualization platform, I have always found it to be extremely flexible, and extremely powerful…and it’s High Availability features are unparalleled in the virtualization world (think live migrations, absolute zero downtime). However, in the course of building out a usable XenServer Cluster here at SevenL, we’ve hit a nasty little snag: converting VMs from one platform to another. Now, you would THINK, that with the advent of OVF (Open Virtualization Format), any snags in converting from, say, ESX to XenServer, would be a thing of the past. Sadly…an open format is only as good as its implementation. Also sadly, both VMWare and Citrix have yet to really provide rock solid implementations of the OVF format.

So where do we go from here? Well, unfortunately, because of the lack of support from both companies, new solutions to a problem that (at least, from where I sit) shouldn’t even exist in the first place must be found. Software DOES exist from both camps that claims to be able to convert from one platform to the other painlessly…but from experience here at SevenL…I can tell you that is anything BUT the case.

Having said all that, XenServer is still a clear choice for us going forward, but we are still working the kinks out. I will say this though, once it’s all ironed out and ready to go, the performance boost will wow all of you…just you wait and see.

So, I guess at the end of the day, This blog post is both a cautionary tale, and an open letter to Citrix, VMWare, and any company looking to adopt an open format….if you’re gonna do it, take the time to do it right. Because Open Source is only as useful as its implementation.