When server maker Hewlett-Packard bet the high-end server farm on the Itanium architecture more than a decade ago, it was also betting that the industry would, too. And, given the slew of endorsements that the industry gave for Itanium way back then, this all seemed reasonable. But Itanium has not gone mainstream - not like X64 processors have, anyway - and one of the side effects of this is that neither the Xen hypervisor from XenSource or the ESX Server hypervisor from VMware support the Itanium architecture.
Luckily for HP, it was a systems vendor long before it gave up on chip design, and its high-end HP 9000 servers, which ran the HP-UX variant of Unix, had virtual machine partitions (vPars) and hardware partitions (nPars) before VMware burst on the scene and before Xen was more than just a thought fleeting through the heads of computer science researchers at the University of Cambridge.
A number of years ago, when HP was making the shift to Itanium-based Integrity servers for both the HP and Compaq enterprise systems lines, the company put into place a plan to take the hypervisor underneath HP-UX and make it a general-purpose hypervisor, now called the Integrity Virtual Machine, that could support HP-UX, Windows, and Linux atop Itanium iron. The management tools and other systems software that wrap around the Integrity VM, now known as the Virtual Server Environment, or VSE, are being improved once again today, as is the underlying hypervisor.
With VSE 3.0, HP is supporting HP-UX 11i v2 and the relatively new 11i v3 versions of its flagship Linux as guest operating systems within partitions on Integrity machines right now. Windows Server 2003 Enterprise Edition and Datacenter Edition, with either Service Pack 1 or Service Pack 2, are also supported, and Red Hat's Enterprise Linux 4 Update 4 will be supported sometime in the next few weeks.
According to Ute Albert, manager of virtualisation at HP, Novell's SUSE Linux Enterprise Server 10 is being certified for the Integrity VM right now and is slated for later this year, and OpenVMS will eventually be tweaked to run atop this hypervisor as well. (The Xen project was working on support for the Itanium architecture, but no one talks about this anymore.)
The Integrity VM hypervisor can allocate processor cores and main memory blocks for virtual servers running on Integrity boxes, and dynamically change these allocations as well as for shared I/O resources. With VSE 3.0, the Integrity VM hypervisor can have up to 20 virtual servers per Itanium processor core, and HP has tuned the hypervisor to offer the best support four cores per virtual machine.
Each virtual machine can support from 512 MB to 64 GB of main memory, but even though the memory is virtualised, every byte of memory has to be physically present to keep memory errors from happening. (You cannot over subscribe on memory, basically, which you can do on CPU cores and other I/O.) Multiple virtual machines can reside inside of a hard partition (nPar), but a virtual machine cannot span multiple nPars.
In addition to adding more recent support for operating systems — which is obviously a work in progress - the VSE 3.0 stack also has other tweaks. Albert says that HP has improved the related Integrity Essentials Capacity Advisor tool, which makes it easier for IT managers and system administrators to plan the consolidation of outboard Unix servers into virtualised HP-UX slices running on Integrity boxes - with a particular emphasis on Sparc boxes running Solaris from rival Sun Microsystems. Albert says that HP has generated more than $1bn in sales of servers, storage, software, and services since 2004 with its Sparc replacement program, and the tweaks in the Integrity Essentials tool are intended to keep the money rolling in.
The capacity planning tool does not yet know how to give advice on consolidating AIX workloads, but it does know how to consolidate older HP environments - HP-UX and OpenVMS - onto the boxes as well and ensure companies deploy enough capacity to support these workloads.
The Global Workload Manager, which is another feature that started out in HP-UX and that now spans the other operating systems that run on Integrity machines, has also been modified so it can automatically access spare capacity inside the machines and prioritise workloads to minimise the activation of latent resources in the box that can be turned on through HP's Instant Capacity on Demand utility computing features. The Global Instant Capacity feature, which was announced last September and which allows processing capacity from one physical machine to be activated on another physical box, now allows for resource rights to be transferred from a server that is offline to one that is online.
Additionally, HP's ServiceGuard high availability clustering software for Integrity machines has been updated so it can provide failover for Integrity VM instances running Linux on Integrity servers and on VMware ESX Server instances running Linux on ProLiant X64 servers. The individual Linux instances inside of an Integrity VM can be moved with this setup; on Windows-based VMs, the whole VM has to be failed over, not just the operating system running inside of it.
Finally, HP has announced a partner virtualisation program, which allows independent software vendors who want to certify their code for the Integrity VM hypervisor a virtual slice of an Itanium-based box so they can run their tests and do their certifications. HP is allowing ISVs to reserve a few month's time on Integrity machines running in data centres in the United States, Europe, and India; these partitions come with two or three virtual CPUs and enough memory to load and test code. The virtual slices are available to ISVs worldwide.