Virtual warfare
Virtual warfare
July 01, 2005: There is no doubt that the concept of server virtualisation is a very appealing one, simply because it allows users to control multiple servers from one central physical computer, instead of having to tamper with each individual system. But customers face some difficulty in deciding which is the best virtual server system to use. Rodney Appleyard analyses the differences between two of the biggest players in the market at the moment: VMware and Microsoft Virtual Server 2005.
The main purpose of VMware is to create multiple virtual servers inside one physical server. It does this by providing a virtualisation layer between the x86 server hardware and virtual servers. This means that each virtual server can contain its own applications and resources inside the physical server, as if it was an individual machine itself.
Therefore, applications and resources can be virtually transferred from one virtual machine to another inside the physical box. This saves on hardware and enhances business continuity, because applications on each individual virtual server can be supported by applications on other virtual servers, inside the same box.
The versatility of VMware enables systems based in branch offices and data centres to be consolidated, regardless of the applications. For instance, Exchange SQL Server, Notes and Oracle can all be combined together inside a virtual server, whilst running on different operating systems. And all of these systems can all co-exist inside an enterprise-class server, such as a blade server. This process can be multiplied several times.
VMware's advantages
Jim Lennox, the director of VMware for APAC, is proud of how much his company has already achieved in such a short space in time. He praises the VMware systems for their ability to consolidate servers, conduct virtual test and development exercises and provide a safe environment for business continuity and disaster recovery.
"We've been selling this product for seven years now and 18 percent of the Fortune 100 companies use it, which just shows you how successful it's become. The space in this area is opening up 75 percent each year too. The vision was ultimately to roll out services independent of the hardware and software layer."
VMware offers two different systems for its customers: VMware ESX Server and VMware GSX Server. The GSX Server can run as its own operating system, independent of Windows, Linux or any other system, whereas the ESX Server has to run on one of these operating systems.
Ryan Goessling, a systems software specialist for CalPERS, which provides retirement and health benefits, says that without GSX Server, his company would probably have at least 85 more physical servers than it does now since he has found it so hard in the past to run more than one application on a system.
"Now, we can set up a new virtual machine in a couple of minutes instead of the several hours it takes for a physical server, and our end users never notice because performance is not compromised."
VMware VirtualCenter provides a central point to control all of the virtual computing resources. Some of the key features of this system include its ability to monitor and control all VMware servers and virtual machines from a single view or "dashboard".
Virtual machines can also be created and configured through this system and it allows the machine resource usage to be adjusted here too.
Josh Heller, the senior technical specialist for power tools manufacturer Black & Decker, adds that VMware ESX server is a critical technology for his IT operation.
"We've been able to prepare for a highly-cost effective rollout of Exchange 2003 to our other business units because we only needed to buy two physical servers to provide a central directory, instead of eighteen. We expect the new Virtual SMP capability of ESX Server 2 to help us get even more benefits from virtualisation."
In addition, VMotion, virtual machine migration technology, enables administrators to move a running virtual machine from one physical server to another. According to VMware, this enables administrators to respond quickly to changes in workload demand and perform hardware upgrades or maintenance with minimal impact on workload delivery. VMware claims that a virtual machine handling 100 orders per second could be moved from one physical server to another in less than a minute without stopping the database application and without losing any transactions.
Microsoft Virtual Server 2005 advantages
Microsoft Virtual Server 2005 is designed specifically for compatibility with Microsoft Windows Server 2003. It aims to allow administrators and developers to have the ability to automate, configure, integrate and manage virtual machines. It is also built to meet server consolidation needs to streamline departments, branch offices and infrastructure services, and provide compatibility for legacy application when re-hosting onto virtual machines that run on Windows Server 2003.
Microsoft purchased its virtual machine technology by acquiring Connectix. Microsoft Virtual Server 2005 is the server version of the Connectix technology.According to research carried out by Ideas International, an international analyst company, Microsoft is targeting software developers, which might make an impact on VMwareÕs current lead in the market. Bill Moran, the senior analyst and vice president for Ideas International, provides evidence from the report that outlines this observation:
"Virtual Server will certainly make the testing job less onerous in a software development environment. For example, the tester would be able to simulate an environment of distributed applications, where performance is usually not critical, on a single server.
"Certain production environments can also benefit from Virtual Server. For example, an installation may have legacy Windows NT 4.0 applications that they are unable to move to Windows Server 2003 for some reason. The customer might consider moving these applications to Virtual Server, along with a hardware upgrade to alleviate performance concerns."
The current state of play
Although the research shows that Virtual Server 2005 would probably be well received by developers, the findings were not all good for Microsoft.
"It is fair to say that although Microsoft may have a virtualisation strategy, the company has not described how Virtual Server will fit into that strategy. Depending on the installation's plans, this could be a key advantage for VMware, which has described an extensive vision for how customers benefit from virtualisation products," continues the Ideas International report.
David Allinson, the Windows Server product manager for Microsoft Australia, defends Virtual Server 2005 by stating some of its key advantages over VMware.ÒCompared with VMware, Virtual Server 2005 offers close integration with Windows Server 2003, which as the host operating system, provides customers with the broadest, most robust compatibility with industry-standard hardware, device models, protocols, remote access methods and automation environments.
"Virtual Server offers a higher level of automation (richer API with significantly more calls), enables customers to automate the product's configuration, integration and management and leverages a single, continuous architecture that spans desktop and server lines."
However, VMware's Jim Lennox looks to turn this argument on its head by saying that VMware has greater advantages because it can be used on so many more systems than Virtual Server 2005.
"The reason why we have an advantage over Virtual Server 2005 is because we can be rolled out over multiple platforms, whereas Microsoft's package is only limited to Windows 2003. There are also problems with the architecture and design when it runs applications on 2003. It is more difficult to schedule activations.
"We run our operations as open as possible, allowing our users to control every guest operating system. We also have a very good relationship with HP and IBM. Our systems are very compatible."
Lennox adds that VMware is also more capable of coping with data centres and high availability applications; backup services; and storage systems.
"We maximise the customer's ability to consolidate many servers onto one box, reducing management by 80 percent. Gartner predicted that those companies who do not use virtualisation technology such as ours by 2008 would pay 15-20 percent more. We can add servers at the click of a mouse button. We are expecting some more improvements to be put in place by the end of the year. These will include automation services for VMotion, where the system will automatically find more power from other servers when running highly intensive applications."
The customer is always right?
Michael Page, the chief manager of open systems at St. George Bank, backs up Lennox's comments by pointing out the areas where VMware has helped his company with server consolidation and disaster recovery. He currently has 70 virtual machines in development, running on one system, which he has been using for the last 12 months.
"We are currently using GSX in development to control the hardware independently of the OS system. We used to control the machines individually. This makes life so much easier. We also have some machines running on Microsoft systems, which VMware can deal with.
"VMware allows us to move applications and resources around at will and it is very beneficial for disaster recovery purposes. It means that we can we have data backed up on other systems, and we can move it across if one system goes down. But of course the major benefit is in the reduction of the number of servers that we need."
Page has also been pleased with how robust the system has been so far whilst it has been in testing. He was initially cautious about using the system, but he is now excited about the potential for it to help aid business continuity.
"We are hoping to have a couple of systems in production by September, 2005."
Mark Jones, the network and operations manager for Corporate Express, which supplies office essentials to businesses, also praised VMware for the difference it has made to his company.
"We were facing the challenge of rapid acquisitions and our servers were growing dramatically as a result. This meant that we were running out of physical space in the data centre, and were thinking of re-locating. However, we already had VMware in trial and we decided to expand its use to help us overcome the problem.
"Whilst in testing, we tried to break the VMware system, but it turned out to be too robustness for all of our tests. After this, we bought four IBM servers, and started to deploy virtual servers. We initially had 25 running but now we have 85 virtual servers in action. This has saved us a substantial amount of money and the level of administration required has reduced enormously too."
Jones adds that VMotion has also helped to move resources between servers when one system is dying, without any disruption to any other systems, so that maintenance can be done to fix the problems.
"It has exceeded our expectations and it has saved us from having to find another data centre, because we did not run out of physical space in the end. We have been using it now for 18 months and we cannot wait for whatÕs coming ahead from VMware."
The research carried out by Ideas International, also backs up comments made by Lennox, Page and Jones, to a certain extent, by pointing out the limitations in Virtual Server in relation to memory handling. The research found that it does not dynamically add or subtract memory from the virtual machines, which means that a virtual machine must be allocated its maximum amount of required memory from the outset. This limits the number of virtual machines that a system can support and installations may have difficulty consolidating low-usage applications into a single system.
There were not any Microsoft customers available in Australia to comment.
Microsoft - it is not all about virtualisation
But one of the disadvantages for VMware is the fact that Microsoft will not support it. This means that if a problem is found in a VMware virtual machine environment that is running on a Microsoft operating system, users will have to recreate the problem on a system outside of the virtual environment before Microsoft will recognise it.
Jim Ni, lead product manager for Microsoft in the U.S., spoke strongly in the defence of Virtual Server 2005.
"Virtual Server 2005 is the best supported virtual server product on the market. We provide a much more complete service than VMware because we look at each individual company's needs and tell them whether they need to use a virtual server, or are better off using another system to manage their resources."
"Whereas VMware only offers you one choice, which is virtualisation, we can recommend six different options that include server virtualisation. We provide a whole host of tools to help users consolidate applications. And we offer the most comprehensive advice and support for organisations. For example, we offer tips to branch offices that need guidance on how best to consolidate their applications in different locations."
Ni adds that that there is sometimes a place for virtualisation and sometimes a place for a different method.
"If you have a high transaction database, then maybe virtualisation is not appropriate for this scenario. Instead, an organisation might be better off consolidating files onto Windows Server 2003, or using multiple SQL servers on top of each other or combining Exchange Servers. At the end of the day, the end goal is about consolidation, not just virtualisation."
Ultimately, Ni believes that VMware is a good solution for some customers, but Microsoft's Virtual Server 2005 is more appealing because users only have to turn to one vendor to fix their problems, whereas he sees that there is a disadvantage in having virtualisation spread across multiple systems made by different vendors.
Virtual choices
Overall, Ideas International's Bill Moran believes that VMware has stronger functions than Virtual Server 2005, such as the ESX Server being capable of eliminating a layer of overhead that Virtual Server incurs, since it does not run under another OS.
"VMware comes as a stand alone system with the ESX Server, which makes it less prone to security attacks than Virtual Server. VMware also has the advantage of VMotion, which allows it to move resources around much more easily. But there are problems with ISVs for both. They do not support problems with applications that are virtualised, although they will still charge a customer for five different copies of software, even if those five copies are virtualised under one system.
"These ISV's also demand that if a problem exists virtually, it will have to be recreated on a real machine. Virtual Server 2005 is a decent product, but it's not as mature as VMware. However, both of them will have problems running very heavy-duty applications, such as databases, Microsoft Exchange or SQL Server. This will degrade systems because they chew up too many resources. But this could change in the near future. Intel and AMD are planning to come up with hardware assist packages that will allow virtualisation machines to process higher duty applications more efficiently for both versions."
On reflection, Moran says that if a user has many different systems, such as Linux and Unix, then that person is better off using VMware because of its superior functionality and ability to work on many different formats. However, if a user has mainly Microsoft applications and a little bit of Linux, then it is best turning to Virtual Server 2005, because Microsoft will not support VMware being used as a virtualisation system on its operating system, although Virtual Server 2005 will be usable on Linux systems.
Moran believes that VMware is going to maintain its market lead in the future, but Microsoft will probably win over many customers because of the wide use of Microsoft around the world. But VMware will need to keep improving its technology to maintain its lead when Microsoft eventually does catch up.
This view is shared by the results found by the Ideas International survey:
"The question then will be how much the products affect VMware when Virtual Server matures. In this regard, Virtual Server is likely to cut off some of VMwareÕs potential growth. VMware will have a strong foothold in the Linux camp, and Virtual Server presents no threat in that direction. Unless VMware somehow encounters serious technical difficulties with a future release of Windows, either as a host or guest OS, VMware should continue to prosper."
Moran added that originally, VMware tried to work with Microsoft, but Microsoft turned this opportunity down and decided to confront VMware head on instead. In the future, he can see another competitor stepping into the space: Xen, which will be an open source virtualisation system, currently being developed at Cambridge University. This will eventually be available to users for free. At the moment, the hardware suppliers, such as IBM, Dell and HP are agnostic and co-operative with VMware and Microsoft, but the battleground between VMware, Microsoft, and ultimately Xen, is set to intensify.
Sun Microsystems is looking to incorporate Xen into its current server virtualisation product: Solaris Container. Although Solaris Container is only usable with Sun's Solaris systems, Sun claims that it is more robust than VMware and Microsoft. Robert Becker, the product business manager for servers and workstations in ANZ for Sun Microsystems, says Solaris Containers can be run on much more resourceful intensive systems.
"It works differently to VMware and Virtual Server 2005 in that it can tell when a system reaches its CPU threshold. It then goes looking for additional resources that are not being used elsewhere, across the containers, to help boost systems that need more capacity. 8,000 containers can be run on one server, but nobody is ever going to need that many.
"Another advantage for Solaris Containers is that it is free to download, so there are no licensing costs involved. We are also working with project Xen. Once the testing for this has been completed, we will probably incorporate it into our Containers, so that we can provide a server virtualisation system that can run on any system. We think this will be much better than VMware and Virtual Server 2005, not least because it will be free."
As for now, it seems that VMware has still got a strong foothold in the virtualisation server market, and although Microsoft Virtual Server 2005 has the potential to win market share due to the number of people who use Microsoft systems, its technology does not seem to quite match up with VMware's. However, the capabilities of Sun's Solaris Container server virtualisation systems, combined with the open source provisions of Project Xen, will definitely create an interesting chapter in the market. It seems that this system will be able to match VMware in terms of technology, but what is even more interesting is that it will be available for free. Customers should pay close attention to the developments of Xen as testing continues.
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