Virtualisation firm Parallels is looking to compete in the enterprise market by offering capabilities that are not available from its rivals. The company has the only product supporting Apple’s Mac OS as a guest operating system, and is now bringing to new markets its container-based technology that is claimed to offer greater efficiency than other solutions based on hypervisors.

In June, Parallels made available its Parallels Server for Mac software, which enables Apple Xserve systems to host virtual machines running the native OS X server “Leopard” platform, as well as Windows or Linux.

Virtualisation is a common technique in Windows-based server environments, where it is used to consolidate workloads and allow for faster failover and disaster recovery. However, it has not so far featured on Mac systems, chiefly because until recently Apple’s licensing policy for OS X did not permit multiple copies to run on the same machine.

Parallels believes that with virtualisation support, Apple’s Intel-based Xserve hardware will now prove attractive to businesses, even large enterprises.

“Historically, Mac servers haven’t been useful because of their limited application support, but now you can consolidate any workload – Leopard, Windows or Linux – on an Xserve,” said Parallels chief executive Serguei Beloussov. Apple’s licensing still prohibits its software being used on non-Apple hardware, so while an Xserve can play host to Windows virtual machines, the reverse is not true.

It goes without saying that Mac servers integrate well with Mac desktop systems, and a small but growing number of companies already operate a mixed environment of Windows and Mac clients. This should also lead to an increase in Mac server adoption in future, Beloussov said.

“More and more people are turning to Macs, even in enterprises, because they have used OS X on the iPhone and liked it,” he said.

Parallels Server for Mac is available immediately for £505 per system, running on an unlimited number of processor cores.

Meanwhile, Parallels also announced in June a partnership with Quest Software’s Provision Networks division to provide enterprise customers with a complete package for virtualisation of Windows client systems.

The move combines Quest’s Virtual Access Suite (VAS) for desktop brokering and management functions, with Parallels’ Virtuozzo Containers providing the virtualisation layer.

VMware and Citrix already provide similar virtual desktop infrastructure (VDI) solutions, under which desktop PCs are consolidated into the datacentre as virtual machines.

Virtuozzo Containers, however, provide virtualisation at the operating system level rather than creating entire virtual machines, as is the case with hypervisor-based rivals such as VMware and Microsoft’s Hyper-V. This offers better performance and scalability, according to Parallels.

“With a hypervisor, you lose a great deal of efficiency, and so you might get 10 virtual machines on a £10,000 server. That means

that instead of spending £250 per user [on a desktop PC], you are suddenly spending £1,000,” said Beloussov.

Under the container-based approach, each virtual desktop is a separate instance of the underlying operating system. As a consequence this means that all users will be patched to the same level, since patching the host also patches the containers, which simplifies management of the virtual desktops.

A typical deployment will use Windows Server 2003 as the host, but templates applied to the containers mean that users see the XP desktop, according to Beloussov.

“Windows XP and Windows Server have the same kernel. Users are getting the Windows Server kernel, but the Parallels Virtuozzo Templates package set makes it look like Windows XP for all intents and purposes,” he said.

Butler Group senior research analyst Roy Illsley agreed that the container-based approach has scalability and patching advantages, but argued that there are also drawbacks.

“The containers are not as well isolated from each other as the virtual machines are under a hypervisor – it is basically the same OS sliced up,” he said. It is therefore possible that a problem might develop in one container and bring down the host, he added.

This may not be a problem if workers are just running productivity applications, Illsley said, and so a company may decide the cost savings outweigh the risk of occasionally having to re-boot the host server for some users.

Moreover, this potential drawback has not prevented Parallels from finding other takers for Virtuozzo Containers. Earlier this month, HP announced it will offer the software to customers running its HP Integrity servers, a move it said will enable firms to achieve greater utilisation of hardware resources when consolidating performance-sensitive Windows and Linux workloads.

Although VMware and Citrix already have VDI offerings, Illsley said that Parallels is not directly challenging them.

“I don’t think they are competing with VMware – it’s about having the right technology for the job. Parallels is making the point that there are situations where you want multiple versions of the same OS,” he said.

The real challenge, according to Illsley, is management.

“If you have a mix of VMware, Parallels and Microsoft virtual machines, how do you oversee the lot of them? No single management tool supports all of these platforms,” he explained.

Beloussov agreed on the importance of management, pointing out that Parallels and Quest had carefully integrated their respective technologies so they work seamlessly together. “We just provide the containers, and they provide the connection brokers and management tools to make a complete solution,” he said.

Quest’s Virtual Access Suite offers features such as automated provisioning, Active Directory integration, power management, support for application streaming, as well as advanced brokering and arbitration.

Beloussov said that the new virtual desktop package is available immediately from either Quest or Parallels. It costs £86 per user, plus £17.20 per user for one year’s maintenance.