When Citrix Systems shelled out $500m a little more than a year ago to buy XenSource, the commercial operation behind the open source Xen hypervisor, the company made it clear that it was going to put Xen at the heart of its systems software, mixing and matching it in interesting ways with other products.
Today, Citrix is going to start positioning its software stack for so-called cloud computing while also at the same time rolling out a new version of its XenServer hypervisor and related management tools.
The updated Xen commercial stack, collectively called XenServer 5, has 130 features and tweaks, according to David Roussain, vice president of product marketing for the Virtualization and Management Division at Citrix. The most important updates are for new operating systems, and XenServer 5 supports Microsoft's Windows Server 2008, Red Hat's Enterprise Linux 5.2, Novell's SUSE Linux Enterprise Server 10 SP2, and the CentOS 5.2 clone of RHEL 5.2 as guests atop the Xen hypervisor. (In both 32-bit and 64-bit variants.)
A little more than a year ago, XenSource was going to use the Veritas Foundation file systems and related clustering and high availability software to underpin Xen hypervisors. But in the wake of the XenServer 4 release, and just as Citrix jumped into the buy the company, that strategy was shown the wastepaper basket. Instead, Citrix decided that the best way to support Xen was to have customers use the file systems, storage array software (snapshotting, thin provisioning, replication, deduplication, and so forth), HA software, and disaster recovery products they had already bought for their servers and storage arrays.
And so the object of the past year has been to get XenServer certified as being compatible with as many disk arrays as possible. This time around, with XenServer 5, support for 8 GB/sec host bus adapters from QLogic and Emulex have been added to the mix, allowing XenServer to talk to most SANs - support for Dell's EqualLogic disk arrays (which it attained through its own acquisition) is also added with this version of the hypervisor. Citrix is also touting a partnership with Marathon Technologies, which has licensed the base code to Citrix for its everRun FT tolerant clustering for virtual machines. Once customers try out this FT software, which allows for hot failover of VMs from one server to another one, they can upgrade to the full everRun FT product from Marathon, which has a lot more bells and whistles.
The XenCenter Management System inside the XenServer 5 software stack now also allows for VMs to be tagged with metadata that lets them be sorted and categorized in a number of ways, such as where they are physically on the network, what software they contain, or what service levels they require. XenCenter now has what Citrix is calling persistent performance monitoring, reporting, and alerting, which keeps and displays historical VM and underlying physical server performance data. These features help system administrators wrestle with virtual machine sprawl and physical servers, too.
All of these kinds of updates are to be expected with any systems program, of course, and the steady beat of tweaks and updates for XenServer is one of the reasons why over 250,000 servers are in production using XenServer today. This is a pretty good ramp, considering that XenSource probably had its commercial products on fewer than 10,000 machines when Citrix bought it a year ago. Still, Citrix has a long way to go before it can catch VMware, and with Microsoft giving Hyper-V away, there is little doubt that Microsoft will soon be the volume leader in the server virtualization space - especially when you consider that around 90 per cent of the machines running VMware's ESX Server hypervisor are being used to virtualize Windows instances. Both VMware and Citrix have a serious race on their hands with Microsoft.
Citrix is not budging on prices yet, despite Microsoft's moves. XenServer 5 costs the same as the previous version. XenServer Express is a freebie version that gives the basic hypervisor and XenCenter management tool; XenServer Standard adds resource pools, and costs $900 ($990 outside the U.S.) for every four server sockets in a machine; XenServer Enterprise adds XenMotion (which allows running VMs to be teleported around the network) and HA clustering and disaster recovery, and costs $3,000 ($3,300 outside the States); and XenServer Platinum adds dynamic workload provisioning and costs $5,000 ($5,500 if you are not American).
What's really new this week - for loosely defined uses of the word new - is a stack of software called Citrix Cloud Center, or C3 for short. Like every other server and system software vendor, Citrix has caught the Web 2.0, SaaS, Web 3.0, cloud computing, and related buzzword viruses. The Citrix Cloud Center stack brings together a bunch of existing Citrix products and the new XenServer 5 to create an integrated cloud computing management tool. (Well, so Roussain says. The market will decide, if cloud computing becomes a market that is somehow distinct from what we used to just call "distributed computing.") The C3 stack includes NetScaler, a Web traffic acceleration tool that Citrix has been selling for years, and which, Roussain says, 75 per cent of end users on the internet go through each day. The stack also has a related program called WANScaler, which shapes and manages network traffic, and Citrix Workflow Studio, which orchestrates how XenServer VMs are deployed on a cluster of computers and how NetScaler and WANScaler cache data and shape traffic.
The C3 software includes two new variants of the XenServer hypervisor. XenServer Cloud Edition is functionally the same as XenServer 5, but instead of being priced based on a four-socket server configuration, the cost will be based on the number of virtual machines it manages. It is basically the same as XenServer 5 Platinum Edition. There will also be an Open Edition, which includes the open source Xen hypervisor, optimized I/O subsystems and drivers, support for Windows guests (with their own optimizations), and a software development kit. (Interestingly, the open source Xen hypervisor is underneath the EC2 compute utility created by Amazon, which does not use the commercial XenServer products for this.)
For now, Citrix is looking pretty eagerly at clouding infrastructure workloads out there in the commercial data centers of the world. "There is a land grab right now in the infrastructure part of the market, and we need to get our products out there," says Roussain. The C3 stack is also suitable for SaaS and other kinds of Web applications, too, obviously.
Pricing on the C3 stack has not yet been announced, but presumably there is a discount for bundling. Roussain says that XenServer Cloud Edition will also have a revenue sharing component in its pricing - meaning if you make dough using it, you owe Citrix some of that dough - but the specifics are not yet available. IBM has been doing revenue sharing pricing on services engagements for years, so it stands to reason that software vendors want a piece of the recurring revenue stream they help to create. ®