VMware aims for datacentre unity

VMware's vSphere 4.0, released just over a month ago, is aimed at helping VMware stay at least two steps ahead of Microsoft, now its biggest competitor in the virtualisation market; VMware's previous move in this perpetual dance was to make its core hypervisor ESX a free download.

So I went to talk to VMware to find out more, and to get a hands-on demonstration of how it works. The company describes vSphere as an operating system for the internal cloud -- a term you might as well view as synonymous with datacentre, as a VMware exec was ready to admit. The top level story is that vSphere is all about improving the efficiency of the four key datacentre resources: computing, networking, storage, and memory.

vSphere, from the company that's led the server virtualisation market since its inception. is aware of its customers' needs for fast return on investment: the last enterprise IT manager I spoke said that no spending that didn't offer more or less instant ROI was making it through today's tight budget filters. But as VMware's Fredrik Sjostedt pointed out at the demo, there are lots of projects that companies are implementing for that reason, and many of those are making use of virtualisation.

Caveats A few caveats before I get into the demo highlights. The company talks about addressing the internal cloud. And applications for vSphere may not lie within a single datacentre but instead might be spread across multiple datacentres. An example might be an organisation with multiple sites and which has grown through acquisition, and wants to consolidate to achieve efficiencies.

There's also an underlying assumption in a datacentre operating system that there's always adequate hardware waiting to be converted into a virtual resource. This may be the case in your setup – again why not share your experience? -- but, more importantly, there will be servers in production use that you really don't want to disturb. Can you wrap vSphere around the hardware infrastructure and keep the servers running? Sjostedt thinks so.

To the demo. VMware's chief European evangelist, Richard Garsthagen, was keen to show off the automated features of the new software. The product is delivered in four versions, aimed at enterprises from the smallest to the largest, according to Garsthagen.

The vSphere 4.0 demo This is a complex product so there was time to view only highlights, but one feature available across all bar the cheapest editions is Data Recovery, which is designed to manage the VM backup process. It consists of a virtual appliance that does block level, on-the-fly de-duping across all virtual machines (VMs) in the backup store. Security's a big issue of course, and VMsafe consists of a set of APIs that allow third parties to build trusted virtual appliances. These sit between the hypervisor and the rest of the VMs, and have access to all of them. This allows you to run only one common copy of anti-virus software, for example, saving resources, cost and management time. Garsthagen said that all the main security vendors have signed up to develop version of their products for this purpose.

High availability and fault tolerance are key to peace of mind if a virtual environment is to replace a physical one. VMs running mission-critical databases for example cannot be allowed to go down if the underlying hardware fails, or there's a software glitch. VMware's answer to this is two-fold.

First is VMware HA -- not a new feature -- which restarts a VM on another server in the event of failure, with some downtime as the server reboots. HA is available in all versions.

"Very hard to do", was how Garsthagen described the company's effort to develop vSphere's fault tolerance feature, available only in the top three levels of the product. The idea is that if a VM goes down, users don't notice the very brief switch-over between the old and new VMs.

FT works by created a second VM that's kept in lockstep with the production VM using code that captures all instructions at CPU level, and shoots them over the network to a second VM in real time. Garsthagen said FT uses proprietary technology and couldn't give further details other than that FT uses a form of encoding or compression.

The demonstration I saw showed only a momentary interruption between a blade server being powered off and the fail-over VM kicking into life. One blogger, Rodney Haywood, points out that the disk must first be prepared first.

Adding to the high availability story is vSphere's HotAdd feature, which permits the alteration of VM settings on the fly. This cannot take account of how OSes or applications might react to having their memory or CPU allocation changed while they're running, although the demo showed SQL Server undertaking a transaction-heavy task that was maxing out the system's throughput. TPS then jumped upon the live allocation of two more CPUs.

At the top end of the vSphere range are features such as the ability to copy and paste host VM profiles, allowing you to create multiple virtual servers that are near-identical but differ only in IP address and other unique features. Similarly, vSwitch is a distributed virtual switch that allows VMs to move around inside the VLAN group and remain part of the group, where they would have had to be reconfigured as VMware virtual switches moved around with the VM. Other benefits include the retention of a server's port stats across a move, which aids both management and security where firewalls use port stats. IOS jockeys can buy a Cisco virtual switch that allows you to work from the command line.

The demo I saw was impressive: it worked, and the features it offers could bring serious benefits to cash-strapped enterprises IT managers. I say could because, from the enterprises and vendors I've spoken to, there are no fully automated datacentres in production use yet. I'd be glad to hear of one.

Describing how vSphere might be installed in real-world environments, Garsthagen said: “You need to do it without disruption, it's not a rip and replace operation. Instead, you expand from the corner of the datacentre outwards.”

So vSphere offers a lot of potential but no-one is likely to use all of it right now. But after a bumpy 12 months, where the share price and even to some extent its reputation as a technology leader have taken a beating after several seriously high-level departures, VMware looks to be delivering a product that satisfies tomorrow's demands.

Alas, without a full datacentre at my disposal for several weeks with which to test out this hypothesis, I can't be certain....