Server Virtualization Blog - A SearchServerVirtualization.com blog

Server Virtualization Blog:

 

A SearchServerVirtualization.com blog


A server virtualization blog covering virtual machine (VM) management and administration, VMware, Xen, Microsoft, server consolidation and hardware, backup and disaster recovery, VDI (virtual desktop infrastructure) and more.

When not to treat VMs like physical servers

A general rule of thumb in virtual environments is to always treat virtual machines the same as you would physical servers. While this rule holds true in many cases, IT administrators should be aware of some exceptions to this rule. Let’s go over some reasons that you would not treat your virtual machines like physical servers:

  • Patching – You should apply all the same operating system and application patches to a virtual machine as you would a physical server. However it is best to stagger your patch deployments so you do not patch and restart all of your virtual machines at the same time. If you did this concurrently you can cause excessive resource utilization on your host servers which could impact other virtual machines running on the host.
  • Securing – Secure the virtual machine operating system as you would physical servers, in addition you should ensure that you have proper security setup on the host server’s management console that allows access to the VM as well as on the virtual machine files located on the host server’s disk system. It does no good to have tight security inside your VM and have weak security outside.
  • System Monitoring – This is one area that can be very different for virtual servers. There is no need to monitor virtual machine hardware, if you have converted physical servers to virtual machines you should make sure you un-install any hardware management agents from them. In addition virtual machines boot much faster then physical servers. Because of this, many monitoring systems will not detect server re-boots because the boot process happens quicker then the monitoring interval. You may find that you need to adjust your polling interval for virtual servers so you can detect the faster re-boots.
  • Performance Monitoring – Another area that is very different from physical servers. Traditional operating system performance reporting tools are often inaccurate when used on virtual machines because they are unaware of the virtualization layer and the underlying physical hardware. You should always use virtual server specific reporting tools to accurately measure performance on virtual machines.
  • Anti-virus – Make sure you install anti-virus software on all your virtual machines the same as physical servers. Again one thing to be careful of is to stagger any on-demand scans and definition updates as to not overwhelm the host server. Having all your VMs running a full scan at the same time can completely bog down a host server.
  • Backups – It’s OK to backup your virtual machines using traditional operating system backup agents. Always make sure you do not backup too many VMs on a single host at the same time. There are more efficient ways to perform backups in a virtual environment that you may look into to either complement or replace traditional backup methods.
  • Disk defragging – You should periodically defrag virtual machine disks using traditional operating system tools for maximum performance. However be careful not to defrag a VM that has a snapshot running, doing this can cause the snapshots rapidly grow in size and degrade host performance. As usual do not defrag more then one VM on a host at a single time because of all the excessive disk activity that is causes.

Be careful not to do too many of the same operations concurrently. With physical servers, only a single server is effected, but in virtual environments many other servers running on a host server can be impacted.

Performance management’s next frontier

Megan Santosus is a features writer for SearchServerVirtualization.com.

VMware Inc.’s recent acquisition of B-hive Networks is indicative of just how much of a wrench virtualization has thrown into the performance management arena. (To recap: B-hive’s Conductor software monitors application performance across virtual environments.) “First and foremost, the acquisition shows the importance of being able to manage performance in a virtualized environment,” said Trevor Matz, the president and CEO of Aternity Inc., a provider of end-user performance management software. “The system metrics normally associated with performance tools are pretty meaningless in virtual environments.”

Traditional performance metrics — CPU, memory usage — that are used to monitor the performance of the hardware that provides service to end users don’t have much relevance in virtual environments, Matz said. “Those metrics are associated with a host machine or virtual box itself and don’t indicate what the end user is experiencing,” he added.

Matz said that Citrix Systems Inc., Microsoft and Parallels are all at work on creating tools that collect meaningful metrics in a virtualized environment. “Having comprehensive tools is not enough,” Matz said, adding that there are already more than enough metrics to parse through. “The next big frontier is the ability to transform huge amounts of data into actionable business intelligence that correlates across platforms.”

Symantec, Citrix take on VMware with block storage management product

On Monday, June 9, Symantec Corp. of Cupterino, Calif., announced the release of Veritas Virtual Infrastructure (VxVI), a server and storage virtualization product built on Citrix Systems Inc.’s XenServer technology. By exploiting Veritas’ block storage management model, VxVI hopes to compete with VMware-Infrastructure-3-in-production environments by offering increased capabilities for storage and availability-critical systems.

The new Xen-based virtual infrastructure platform from Symantec provides storage management and high availability with cross-platform connectivity for the virtual data center. It’s essentially XenServer with the Veritas storage management layer on top — all wrapped in a Symantec management console.

According to Symantec Senior Vice President of Storage and Availability Management Rob Soderbery, the time is right for a product that addresses the needs of testing and development, needs that have been underserved by VMware. “Users understand the storage management challenges with VMware,” he said. Symantec has delivered something “fundamentally new” in how server virtualization works with storage management, he noted.

The key difference between VMware and Veritas is in how each handles virtual machines (VMs). Soderbery argues that the Virtual Machine File System (VMFS) file-based system that VMware uses can’t compete with the block storage system of Veritas VxVI.

As enterprises build out the x86 data center, Symantec’s product seeks to serve those who want to bring physical capabilities into the virtual environment. Veritas Virtual Infrastructure brings dynamic storage layouts, enclosure and array mirroring and storage-area network (SAN) multipathing/load balancing to server virtualization, adding features such as shared VM boot images with which Symantec hopes to lure VMware customers that are not satisfied with the storage capabilities of the leading server virtualization platform. 

Soderbery says that VxVI will work well with Microsoft’s forthcoming Xen-inspired hypervisor, Hyper-V. “Microsoft has done something pretty interesting here in being open to the Xen community and encouraging the Xen community to be open with Microsoft,” says Soderbery. “Veritas Virtual Infrastructure is technology that we can apply across the Xen ecosystem and Hyper-V as well.”

With another Xen-based virtualization product on the market engineered to be more compatible with the forthcoming Hyper-V, VMware may feel the pinch as users see more options with the other big players in the server virtualization market. But will the $4,595 per two-socket server for Veritas discourage VMware users from even running a demo?

What do you think? If you plan on deploying Veritas VxVI, we want to hear from you. Send us your thoughts via email.

Hyper-V could benefit from VMware’s Xen-based competition

If Hyper-V doesn’t convert the VMware faithful as soon as Microsoft makes its hypervisor generally available later this year, it may get a little help from its friends: Xen-based virtualization platforms.

Some like IT consultant Ardalan Dlawar believe that Microsoft will leverage support for Xen-based platforms to increase competition with VMware. “And Xen will have more third-party support and fewer compatibility issues,” according to Dlawar.

Despite user arguments that ;Hyper-V will have to deliver more than a lower price tag to win users, Hyper-V will certainly get consideration from many VMware customers. While organizations want to maximize their VMware investment, especially enterprise customers which deploy tens or hundreds of VMware virtual machines, Hyper-V evals will most likely be deployed, according to Andi Mann, the research director at Boulder, Colo.-based Enterprise Management Associates (EMA).

Based on a survey of more than 600 enterprises, EMA found about 30% of enterprises have already planned a Hyper-V deployment even with Hyper-V’s general availability several months away. In addition, Microsoft is actually within 10% of VMware in current and planned enterprise deployments according to EMA’s data. Also consider this EMA finding: Xen-based platforms already account for more than 40% of current or planned deployments, the data suggests that the market demand for VMware alternatives won’t disappear.

“VMware is still way out in front in server virtualization,” said Mann, “but both Microsoft and Citrix Systems are definitely catching up.”

Of course, VMware and Microsoft aren’t the only options available. As managers continue utilizing toolsets available from Xen-based products such as Citrix’s XenServer and Virtual Iron Software, VMware and Microsoft are both working on tool sets that enable users manage their virtualization counterparts respectively.

“Both VMware and Microsoft understand that they are not going to be the only players on the market, they recognize that customers are leveraging their competitors’ technology in different parts of their businesses,” according to Adnan Hindi, the VP of operations at ScienceLogic in Reston, Va. Hindi said that companies like his, which produces cross-platform appliances, will benefit from multiple-platform virtual landscapes. As shops continue to see benefit in the utilities that Xen-based products offer, Hindi sees a universal virtualization tool set ultimately working itself out; these tools would essentially equalize platforms in the market and dilute decision making in choosing a virtualization platform largely down to cost.

Over the past year, there’s been a lot of talk about VMware’s cost of VMware. But the price of VMware Server is right for small businesses, said Brett Riale, an IT consultant in Pittsburgh, who feels “truly blessed that programs as functional as VMware Server have been released for free.” Riale is hesitant to trust another Microsoft virtualization product after “the debacle” that was Virtual Server 2005. “Unless it absolutely outperforms VMware,” Riale said that he won’t consider Hyper-V in the near future. And Dave Baughman, a systems administrator for Muncie, Ind.-based Ontario Systems, thinks that his ESX system is “a consistent platform” and that the price of support is worth their investment. “Most of the cost is for support and (VMware’s) support is very good,” says Baugham.

But what will happen when all the Microsoft customers with enterprise agreements get a taste of Hyper-V support? Or if Microsoft offers more third-party support for Xen?

Howard Holton, a system engineer, said that market share will shift in Hyper-V’s favor.

“Hyper-V is an excellent solution for many of those that cannot afford the steep cost that ESX server requires,” says Holton, who has already has a positive experience working with the release candidate and points out that for most data center operations, VMotion’s High Availability (HA) is overkill. ”Hyper-V fits into the market below VMware for hosts that do not need true HA.” 

Holton said that in the long run Hyper-V might win out over VMware because Citrix’s XenServer has finally given Xen a roadmap. XenServer is the spoiler, with a lower TCO than VMware. Although price hasn’t deterred Holton from delivering VMware to his customers in the past, he predicted that Hyper-V will only increase in value.

“As a value-added reseller in the small to midsized space, VMware is the leading virtualization product that I offer. That is changing.”

Virtualization performance benchmarks needed ASAP, vendors say

Big players in the virtualization world griped about the absence of performance benchmarks for virtual machines on CIO Talk Radio yesterday and discussed some of the issues surrounding virtualization standards.

Guests on the show included: Simon Crosby, Chief Technology Officer of the Virtualization and Management Division of Citrix; Tom Bishop, Chief Technology Officer, of BMC Software; Dr. Tim Marsland, Sun Fellow, Chief Technology Officer, for the Software Organization at Sun Microsystems Inc.; and Brian Stevens, Chief Technology Officer and Vice President of Engineering at Red Hat.

The glaring ommission in this lineup: VMware, Inc.

The panelists on CIO Talk Radio didn’t mention VMware by name, but did complain that some companies aren’t being open with their performance data, thus prohibiting the virtualization industry from publishing comparative performance data.

VMware’s licensing agreement for ESX allows users to conduct internal performance testing and benchmarking studies, and allows those users (and not unauthorized third parties) to publish or publicly disseminate the data provided that VMware has reviewed and approved of the methodology, assumptions and other parameters of the study.

Users that have published benchmark data, like Sr. Systems Engineer Mark Foster did on his blog, have had to unpublish results because of VMware’s stipulations.

VMware introduced its own free benchmarking tool, VMmark, last year for certain applications.

Meanwhile, the SPEC Virtualization Committee has been working to create standard benchmarks for VMs. The committee’s goals are to deliver a benchmark that will model server consolidation of commonly virtualized systems such as application servers, web servers and file servers; provide a means to compare server performance while running a number of VMs; and produce a benchmark designed to scale across a wide range of systems.

SPEC expects these benchmarks to be available by the end of this year, but the timeline is not set in stone, according to the website.

Sun’s Marsland said benchmarking progress has been slow because there isn’t an easy way to define a workload, and a large number of benchmarks are required.

“We are talking about a virtual computer, with lots of aspects that need to be benchmarked,” Marsland said. “Every component that gets virtualized needs to be benchmarked.”

Having an open, standardized way of benchmarking is expected to push virtualization further into the mainstream because it will eliminate false perceptions about performance, panelists said. For instance, “there is the thought that I/O intensive workloads can not be virtualized, and the absence of benchmarks prevents us from proving otherwise. It is important for us to have good benchmarks out there,” one panelist on the show said.

Though users look at benchmarks, this type of data is most useful to vendors and OEMs who can use the performance standards to improve the technology, and of course, market their products.

“More open scrutiny of performance results will help us to improve as an industry overall,” Bishop said. “There are ways to measure performance in non-virtual environments, and people are adapting those techniques to get the most out of their virtualized environments.”

In terms of application performance in virtual environments, the issues differ depending on the data center infrastructure. The network, the servers and the storage all affect performance, said Stevens of RedHat.

“The areas that have to progress are around I/O. Intel and AMD are improving around page tables, and we will see improvements around I/O adapters soon,” Stevens said.

Another problem with virtualization? There are support challenges. If an application running in a VM starts acting wacky, the application vendor may not support it, Crosby said.

Licensing and support in virtual environments has been a major gripe with Oracle, for example, which does not support running its applications with VMware.

“It is a reasonable concern…right now there is irrational market based control. Some folks are abstaining from supporting certain apps [in virtual envionments]. As customers demand support, things will hopefully get rational, by next year I hope,” Crosby said.

Xen: An endangered species in the virtualization ecosystem?

While Citrix Systems’ Xen’s ubiquity may help the technology earn a legacy as the invisible hypervisor, it may also prove the most challenging next step for IT administrators and developers who want to find or develop software that leverages, supports or extends the Xen hypervisor.

To understand the problem that Xen faces, take Java as an example. Java is great, and I am committed to developing applications that are truly cross-platform using what I consider this fantastic creation. But in all the years that Java has been around, it has failed to gain traction that NET has achieved in less time. Why?

Although Java is slower, it offers a greater advantage than .NET in terms of portability; but Java still hasn’t managed to gain a majority mindshare of developers. This is because Java’s true worth is its portability, its ability to blend into any system. Java has succeeded so well at being invisible that it has lost the sexiness associated with languages used to construct desktop and Web applications. Every once in a while, something like the Google Web Toolkit comes along that makes people take a step back and re-evaluate Java’s usefulness for end-user applications. Ultimately, Java has been left to the obscurity of providing enterprise, back-end applications.

Is Xen is destined to a Java-like fate? While ultimately it may not prove difficult to develop cutting-edge technology compatible with the Xen hypervisor, it may prove so to market it. If you are in the business of selling virtualization add-on products, you want to ensure that your product is compatible with VMware Infrastructure, because that is where the sales are.

The marketplace has not been especially kind to Xen for two reasons: it was not first to market, which is an important factor for any industry, and Xen resellers do not have the power of the VMware PR machine. Also, all major virtualization vendors, including VMware, say that hypervisors should be ubiquitous — the difference is that the VMware CEO Diane Greene has been quoted on virtualizationreview.com and in person. VMware shouts the same thing everyone else is casually discussing and this makes headlines.

As Xen’s legacy may be to become the ubiquitous, embedded hypervisor for all to use, its strength may also be its greatest detriment to Xen-based virtualization platforms. Xen’s strength is its practical application as the invisible, reused, resold, embedded hypervisor, but invisibility just hasn’t worked in Citrix’s favor. Instead, it shields partners from building ecosystems around Xen and has marginalized the brand name.

VMware pushes desktop virtualization on management and security benefits

VMware Inc. Senior Director of Enterprise Desktops Gerald Chen visited our office on Tuesday morning to discuss the different types of desktop virtualization and answer common questions about Virtual Desktop Infrastructure (VDI), for example, how it differs from terminal services and cost issues.

Here’s how VDI works: each end user gets a virtual machine (VM) that is deployed from a server in the data center directly to a PC, laptop or thin client computer. Each VM is customizable, so all of the user’s settings are saved and re-booted each time the user signs in, Chen said.

When a user logs off for the day, their VM goes idle, and wakes back up when the user logs into their system again, according to Chen. Chen believes that the advantage of VDI is that sensitive data is not being stored on desktops, which can easily be lost or stolen, and these virtual desktops are easier to manage than physical ones.

“VDI is great for industries like health care that are really concerned about information security and compliance. The real value though, is in management. All of the information is safe in the data center, and centrally managed through Virtual Infrastructure,” Chen said. “For instance, if you have 100 new employees who need desktops, you can deploy a VM for each of them in just minutes, and manage all of them centrally.”

VDI is different from Sever Based Computing (SBC) systems like Citrix Systems Inc.’s XenApp in that VDI is connects a single user to a single operating system (OS), instead of having multiple users share one OS.

“Not every application likes to share an OS, and there is also bad isolation; if one application crashes, everyone sharing that OS crashes as well. Those desktops can’t be customized either. It is a locked environment.”

Chen went on to explain that with VDI, four to ten VMs per server core are supported, so a server with one quad-core processor can, theoretically, house 40 VMs. Of course, that varies depending on things like workload, applications and memory. If the VMs become too heavy for the server to handle, management features in VI3 intervene. VMotion can move live VMs from one server to another when capacity issues arise, as can Dynamic Resource Scheduler, which allocates and balances computing resources as needed using VMotion.

Desktop virtualization case study
As VMware announced customer case studies in February, including one at Huntsville Hospital in Huntsville, Alabama.

The hospital needed to implement a new medical information application throughout its network while protecting HIPAA-related data. Deploying hosted desktops on VMware, the hospital could lock down sensitive patient data and reduce the cost and complexity of desktop management.

They used combinations of thin clients and blade servers to access the centralized virtual desktops, and in turn, reduced power consumption across the hospital by 78%, improved longevity with lower hardware maintenance needs and made wireless thin clients on wheeled carts available to hospital staff. Also, doctors can remotely access their VMs through the Internet using a web browser when necessary.

The downside to desktop virtualization
While the benefits are clear, there are some downsides to desktop virtualization: extra storage and initial cost.

Chen told SearchServerVirtualization.com that VMware is working on reducing image sizes and has designed a way to keep only one copy of files that are identical among many users, like icons and other graphics, to reduce the amount of storage necessary.

The cost of implementing desktop virtualization turns users off. According to Ars Open Forum blogger ‘Bright Wire,’ the cost and the magnitude of system upgrades required is not worth the benefits.

“The cost of deploying virtual desktops is massive,” Bright Wire wrote. “You will need to re-gear your existing desktops to run the virtual or you will need vendor equipment that costs twice as much as a new desktop. Either way, the cost is big in manpower. On top of that, your infrastructure will need serious review.”

According to VMware’s product specifications, local desktop virtualization requires a 500 MHz or faster processor with recommended 256 MB of memory, though Forrester reports that PCs must be faster and have more RAM to work efficiently.

“In addition you need to look into the server infrastructure,” Bright Wire said. “You are talking about needing a lot of iron on the backside to handle the needs of the server to supply two to 16 desktops. All this adds up quickly and can easily swamp a datacenter.”

As for pricing complaints, VMware is used to hearing them and holds firm to the ‘you get what you pay for’ mantra, saying the management benefits are worth the price.

The company charges $150 per concurrent user plus additional costs for support, either Gold or Platinum levels. Both bundles include VMware Infrastructure Enterprise Edition for VDI (which consists of VMware ESX Server 3.5 and VirtualCenter 2.5) and the VMware Virtual Desktop Manager 2. The VMware VDI Starter Edition, which enables 10 virtual desktops, has a list price of $1,500. The VMware VDI Bundle 100 Pack, which enables 100 virtual desktops, has a list price of $15,000.

The market indicates a demand for desktop virtualization, as a number of other vendors also entered the desktop virtualization space including Sun Microsystems Inc., Citrix., Pano Logic Inc. and Symantec. Chen would argue that many customers come for reduction in hardware but stay for the management applications.

“Reducing hardware costs is not a reason to use VDI, it is management. We have customers who have seen 40% to 50% ROI in terms of management costs and the amount of time it frees up.”

Citrix XenServer now shipping in Dell PowerEdge servers

Citrix Systems, Inc.’s XenServer hypervisor is now shipping in Dell PowerEdge servers, following the partnership accouncement in October 2007.

With Dell, initial products available worldwide include the Citrix XenServer Dell Express Edition and Citrix XenServer Dell Enterprise, both of which include Dell’s management software, Dell OpenManage System Management. Express Edition is a free download that can be upgraded to Enterprise edition. 

By factory-integrating the Citrix XenServer hypervisor into Dell PowerEdge platforms, users can deploy virtual machines (VMs) when they start up their systems for the first time. Also, the XenServer Dell Enterprise Edition does not require additional management licenses or hardware. Also, upgrades for features like live migration on Dell’s MD3000 direct attached storage arrays can be made easily, by imputing a license key.

In March, Hewlett-Packard began shipping XenServer embedded in ProLiant servers. HP’s servers also have specific versions of XenServer called HP Select Edition, which differs from traditional XenServer in that it is tied into HP management tools, like HP Insight Control and HP Integrated Lights-Out for remote server management, according to a Citrix spokesperson.

In light of its partnerships with HP and Dell, Citrix simplified its licensing model recently to per-server, instead of per core, as reported on SearchServerVirtualization.com. This way, users can deploy an unlimited number of virtual machines or guest operating systems on each physical server for a single price, regardless of whether it has one, two or four CPU sockets.

Citrix XenServer to ship in HP ProLiant servers

Citrix Systems, Inc. today announced a development and distribution agreement with Hewlett-Packard Co. (HP) to integrate an HP-specific version of Citrix XenServer into 10 models of 64-bit HP ProLiant servers.

Citrix worked with HP to develop a version of XenServer called HP Select Edition, which is different from XenServer in that it is tied into HP management tools, like HP Insight Control and HP Integrated Lights-Out for remote server management, a Citrix spokesperson explained.

Existing ProLiant server users can upgrade and virtualize their servers with XenServer with a license key and USB drive, according to a Citrix spokesperson.

Citrix XenServer HP Select Edition will be available and supported by HP starting on March 31, 2008.

As previously reported on SearchServervirtualization.com, HP started reselling XenServer back in October, but hadn’t agreed to pre-install the virtualization technology into its servers until today. At that time, Dell announced plans to resell and pre-install the OEM edition of XenServer into its PowerEdge servers.

Earlier this month, Lenovo also announced its plans to use the OEM edition in its servers and distribute it in China.

Virtualization strategies for the SMB

The small and medium businesses (SMB) are unique in their approach to virtualization. In attending a recent VMware Users Group (VMUG) meeting it became clear that virtualization is much easier to embrace for the large enterprise, whereas the smaller IT shops have an entirely different dynamic. Here are three strategies currently employed by the SMB while approaching virtualization:

Free tools

The SMB may not have the money to jump into an enterprise virtualization management suite, so the free tools work nicely in their environment. Free tools such as VMware Server, Microsoft Virtual Server, and Citrix XenServer Express Edition offer virtualization at various levels that will generally meet requirements. The free virtualization packages have their benefits, but there also are limitations. These limitations revolve around storage management, high availability and redundancy.

Cite disaster recovery

The SMBs present at the VMUG frequently used disaster recovery to justify the upfront expense for decent virtualization management software. Disaster recovery tends to present a better argument for funding rather than simply stating that management software for virtualization technologies are superior to that of the free equivalents.

All or none

SMBs tend to shoot for an all or none approach to virtualization. If utilizing virtualization, serious reasoning is required to explain why a server can and should not be a virtual system. This correlates to the hardware purchases. In this situation, all new server purchases must be capable of the virtual host role regardless of the immediate availability of the desired end-state of the virtual environment.

It is tougher for the smaller IT shops

The smaller organizations have a particular challenge taking the virtualization plunge due to smaller budgets. The challenge for SMBs is to find a way to justify the expense and not in using virtualization itself-the benefits are obvious. The most difficult step, however is to get a business buy-in for the potential added expenses, and this is where SMBs should focus their efforts if they are trying to convince executives to use a virtualized system.