I took a break from blogging after Citrix Synergy, mostly because I’ve been busy working with customers building interesting private and public cloud services with XenServer 5.6. One such is The Rackspace Cloud, which offers a powerful suite of enterprise-focused services. Their new Cloud Servers for Windows service is now in beta. Give it a whirl here.

You probably know that the largest IaaS cloud, Amazon Web Services, is Xen based. Indeed xen.org estimates that over 90% of public cloud services today are built on Xen. At Synergy Rackspace announced that it is using XenServer for its Cloud Servers service. Why XenServer? Well, XenServer adds many hundreds of enterprise virtual infrastructure focussed features to Xen because it was built to enable enterprises to run any enterprise application in a rich virtual infrastructure fabric. So, in using XenServer, Rackspace has a few advantages over any other virtual infrastructure platform:

  • XenServer is one of only two virtual infrastructure platforms that the Burton Group deems ready to run enterprise production workloads.
  • XenServer is Microsoft SVVP Certified, and so fully supported by Microsoft and moreover is 100% compatible with Hyper-V.
  • XenServer is free, or if you want premium features, charged for on the basis of physical server count, not CPUs or cores
  • XenServer’s management architecture scales superbly, so building a cloud of thousands of servers is no problem
  • XenServer’s storage architecture supports advanced enterprise storage features, including in-array snapshots, cloning and thin provisioning
  • XenServer offers SR-IOV to permit very high performance I/O, including supporting Netscaler VPX.

XenServer has lots of benefits, but perhaps the most important point is that you don’t need to believe me to believe it.

THis week, in its first ever assessment of server virtualization platforms, using its “Magic Quadrant” methodology, the Gartner Group has placed XenServer in the “visionary” quadrant. Nobody will deny that VMware has done a fabulous job of winning enterprise accounts, with high satisfaction in general. But could you ever afford to build a serious cloud using it? To be clear, the largest cloud of which I’m aware that runs free XenServer, counts more than 12,000 servers, 100,000 VMs and is growing like gangbusters. XenServer is (a) free and (b) doesn’t have built-in scalability limits.

Gartner praised XenServer for its leadership in features and price/performance, and (IMO, justifiably) held Citrix to task for its execution on selling the advanced features and monetizing the large base of free XenServer users.

The base? Yes. Large – undeniably – and currently on target for about 18% run-rate market share in virtualized servers, counting roughly 750 servers per day virtualized. This year, we will virtualize between 200,000 and 250,000 servers absolutely free. And this is no free hypervisor, like ESXi. This is free virtual infrastructure: Resource pooling, optimal VM placement, virtualized networking and shared storage, live relo, no downtime maintenance, full management with XenCenter. Everything other than automated, self managing private cloud infrastructure.

Oh, you aren’t using it yet? Why not?