Virtualisation is big news and poised for an even bigger future. Matthew Aslett investigates its potential impact
on storage management.
If anyone had any doubts about whether server virtualisation was a mainstream technology, they should have been dispelled by recent events. In August, VMware made the most successful technology stock market debut since Google, and then Citrix announced that it was to acquire open source virtualisation vendor XenSource for $500m, several hundred times the company’s annual revenue.
The two events are indicative of the growing importance of virtualisation, as well as its potential over the coming years.
Far more than 70% of the world’s large enterprise data centres have VMware virtualisation software installed, according to Carl Greiner, senior vice-president of infrastructure at Ovum.
Meanwhile, IDC estimates that by 2010, almost 15% of the new servers shipped will be virtualised, versus 4,5% of new servers shipped in 2005. The virtualisation market will double during the next five years to almost $12bn, according to IDC.
Stock market debuts and acquisitions are symptomatic of a maturing market. So too, from a technological perspective, are vendors becoming aware that their products do not exist in a vacuum and have an impact on complementary technologies.
This is especially true when it comes to virtualisation. While the technology is designed to simplify server administration by breaking hardware dependency and creating a pool of processing resources on which software can run, this has a knock-on effect on systems management and monitoring, as well as storage management and back-up.
These are issues that VMware began to take seriously in June last year with the release of VMware Infrastructure 3, which debuted VMware VMFS, a new distributed file system; VMware Distributed Resource Scheduler (DRS); VMware High Availability (HA), and VMware Consolidated Backup.
“The main difference, and a major change, is a move away from server consolidation to people designing their back-end data centre infrastructure with this in mind,” says Reza Malekzadeh, VMware director of product marketing and alliances, EMEA.
“Now, instead of mapping between the physical hardware and virtual software, we can aggregate a pool of resources and assign a virtual machine to that. What this gives us is an extremely dynamic data centre.”
Creating a dynamic data centre where processing resources can be applied to applications and operating systems as and when they are required might ease server administration and reduce costs, but it also changes the dynamic between the server and its storage dramatically.
“It does change the picture, but I do not think it makes it more complex,” says Malekzadeh, noting that VMware HA is designed to eliminate single points of hardware failure, while VMware Consolidated Backup simplifies data protection by offloading back-up to a centralised server.
VMware is not the only virtualisation vendor to wake up to the importance of storage management for virtual environments. In August, XenSource announced that it had struck a deal with security and storage giant Symantec through which it will develop unified server and storage virtualisation capabilities.
The deal sees XenSource embedding Veritas Storage Foundation within XenEnterprise to enable unified server and storage virtualisation, while it will also create new high availability and back-up for XenEnterprise virtual environments.
“Storage has always been the next thing to follow server virtualisation and Symantec has already done the plumbing for this,” says Simon Crosby, XenSource founder chief technology officer. “For us to be really credible in terms of supporting the most demanding SANs in the data centre would take years, if we would ever get there. Symantec is the ideal partner in this regard. They are the predominant player.”
Specifically, the deal sees XenSource signing an OEM agreement to embed the Veritas Storage Foundation storage management software within Xen Enterprise, the company’s flagship virtualisation software, which is based on the open source Xen hypervisor.
XenSource will also develop Xen Enterprise High Availability to provide failover of virtual machines, which will be tested for certification by both companies, while XenEnterprise will also be certified for Veritas NetBackup for data protection.
For Symantec, Sean Derrington, director of storage management product marketing, says the results will give users 'a consistent way to manage storage', noting that while server virtualisation enabled users to consolidate servers it also had implications on the wider architecture.
By entering into an OEM deal with XenSource, Symantec appears to have lined itself up against VMware – the virtualisation platform leader, which is still mainly owned by its storage rival EMC – despite its stellar IPO.
XenSource’s Crosby says that was a significant driver for the relationship. “VMware is the runaway success story right now,” he says, adding that VMware’s success is causing concern among some of the larger software vendors as customers buying into VMware’s VI3 get the ESX Server Virtualisation software, as well as VirtualCenter for virtual machine management, high availability and resource scheduling, as well as consolidated back-up capabilities.
“Every part of the infrastructure has been changed to VMware,” says Crosby. “The VMware road show is one that replaces all the other players in the industry. We believe customers who have already invested heavily in storage management software should not have to throw it out. Symantec customers can invest in virtualisation from us and be sure that it will work.
“As VMware gets bigger the potential to disrupt the main players has always been there,” he says. “There has always been a desire for this to happen. Symantec wants to have a major play in virtualisation and not just be a spectator.”
Speaking for the security and storage management vendor, Derrington was more diplomatic, noting that Symantec supports VMware virtual environments and EMC storage hardware, and will continue to do so. “One of the things about being a software provider is we want to enable customers to make the choice that is suitable to them,” he says, declining to be drawn into discussing the merits of VMware’s approach or Symantec’s position with regards to EMC.
Meanwhile, Malekzadeh denies that with VI3 VMware is moving the point of potential lock-in from the operating system to the virtual environment. “We have a firm commitment to working to open standards such as the DMTF [distributed management task force],” he says, noting that the company’s virtual machine disk format specification is openly available.
He also notes that Symantec is already a VMware partner, alongside other back-up software providers including CA, Comm-Vault, EMC, IBM Tivoli and Vizioncore. Indeed, Malekzadeh doubts the wisdom of XenSource picking such a close storage partner.
“I do not think that any vendor should force a customer on any parallel solution,” he says. “We already have a partnership with Symantec, so in effect, XenSource is playing catch-up with that.”
That is something that XenSource would not deny, although with the recently introduced version 4.0 of XenEnterprise, Crosby is claiming 'blow for blow competitiveness with VMware'.
“Version 4.0 is the result of a long project. It is a major step up in terms of features and brings us into the big leagues,” Crosby says. The latest version of the company’s XenEnterprise software features XenMotion for live migration of virtual environments, a new management interface called XenCenter, the Xen64 native 64-bit hypervisor, XenResource-Pools, which offers the automated management of resources, and XenAPI.
The latter is the same application programming interface that is exploited by XenSource partners, and should enable the creation of products that make use of XenEnterprise’s virtualisation capabilities.
“It is a pluggable API that can be used to dynamically insert new storage subsystems and storage types,” says Crosby, noting that it will enable new storage management capabilities alongside those promised by the company’s relationship with Symantec.
“As the Symantec relationship unfolds, Veritas plugs in as a storage architecture for us,” he says. “Symantec is not something we would require but it is certainly an opportunity. We use Xen API for the entire ecosystem.”
One of the fundamental differences in how VMware and XenSource are approaching the market is in VMware’s focus on its own technologies, compared to XenSource’s stated desire to add management capabilities for Microsoft’s forthcoming Viridian Virtualisation soft- ware, as well as the Xen open source hypervisor.
“We do not intend to be the management solution for everything. We are focused on our core competencies,” says Malekzadeh. “At the end of the day, we are not a management vendor.”
This is increasingly what virtualisation software providers are becoming, however. Citrix’s acquisition of XenSource is expected to close in the fourth quarter and will see XenSource form the core of a new virtualisation and management division within Citrix, led by current XenSource CEO, Peter Levine.
The new division will also work closely with Microsoft to create virtualisation management products that run on top of Microsoft’s forthcoming Viridian Virtualisation hypervisor, as well as XenSource’s existing virtualisation technologies, according to Levine.
“Our product focus is to provide the best Microsoft virtualisation experience on the market,” he says. “We are committed to the delivery of a product suite that is compatible with Microsoft’s future virtualisation products.
“We will be building dynamic virtualisation services and management tools on top of Viridian,” he adds. “We will build the same set of products we have built on top of Xen for Viridian. We have already hired a team to do that up in Redmond.”
Another company looking at the bigger management picture is SWsoft, which plans to deliver a combination of its Virtuozzo and Parallels server virtualisation technologies sooner rather than later, according to founder and CEO, Serguei Beloussov.
“We will have them together by the end of the year,” he says, noting that the Parallels hardware virtualisation approach will become a feature of Virtuozzo, and vice versa. “In the management tools you will create a virtual environment, or a virtual machine, but it will be transparent,” he says. “We actually envision that operating system virtualisation will work on top of hardware virtualisation, and definitely alongside.”
Virtuozzo is SWsoft’s traditional operating system-level virtualisation product. It works by creating partitions, or virtual environments, on a single physical server and operating system instance. It enables users to run multiple applications on a single server, with each application acting as if it is running on its own dedicated operating system.
Parallels offers a hardware virtualisation platform. Like VMware and XenSource, Parallels virtualises the hardware via a hypervisor layer that enables users to install multiple operating system instances and applications in separate virtual machines.
SWsoft came clean earlier this year that it is the owner of Parallels, a fast-growing desktop hardware virtualisation specialist that will release its first server products in the fourth quarter. The integration of the two approaches via a common management platform makes sense for SWsoft, given its stated intention to provide management capabilities for rival virtualisation offerings from VMware, Microsoft and XenSource.
The dark horse in the virtualisation space is Microsoft. Its Viridian hypervisor is due to be delivered six months after Windows Server 2008 and both are sure to have a significant impact given the company’s installed base.
However, Viridian will be late to market, and it will also have less features than were originally advertised. “Microsoft is continually shooting itself in the foot. It made the customer wait for Viridian, which is not coming any time soon,” says Beloussov.
Mike Neil, Microsoft’s general manager virtualisation strategy, confirmed in a blog post in May that the company is delaying a number of features for a later release of Windows Server Virtualisation, including live migration and the ability to add resources such as storage and networking without disrupting the virtualised system.
The first version of Windows Server Virtualisation, due for release within 180 days of the Longhorn server, will also only scale to 16 processor cores, rather than the planned 64.
“We adjusted the feature set of Windows Server Virtualisation so that we can deliver a compelling solution for core virtualisation scenarios while holding true to desired timelines,” wrote Neil. “Windows Server Virtualisation is a core OS technology for the future, and we chose to focus on virtualisation scenarios that meet the demands of the broad market: enterprise, large organisations, and mid-market customers.”
While Viridian might still meet the demands of the broad market, there can be no doubt that it has lost some of its major selling points. The loss of the functionality is a significant blow as Microsoft battles with VMware, SWsoft, and XenSource, among others, to be the enterprise virtualisation platform provider of choice, but given its market dominance it is bound to be there or thereabouts.
With VMware dominating the market and Microsoft poised to enter, it is little surprise that the current second-tier specialists such as XenSource and SWsoft are looking to differentiate themselves with management capabilities. It will be a struggle, but XenSource has the backing of Citrix and a close relationship with Microsoft on its side, while SWsoft is growing rapidly in VMware’s slipstream and is poised for significant growth with Parallels. SWsoft also has the opportunity to position itself as the Switzerland of the virtualisation management market. Either way, the market is so young, with so much potential for growth, that there is still time for winners to emerge.