Citrix heads for clouds, HA with XenServer 5
Supports more disk arrays and their software
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.