Start with a Robust and
Reliable Foundation

Every Hypervisor is not Created Equally

The hypervisor is the core foundation for a virtualized datacenter. Contrary to what many vendors who are new to virtualization would like the market to believe, the hypervisor is not a commodity. There are fundamental differences between hypervisors that will impact your experience with virtualization. Your choice of hypervisor will determine whether you are able to introduce virtualization into your IT environment successfully and fully realize the benefits of a virtual infrastructure. Select the most robust, production-proven hypervisor, otherwise you introduce unnecessary risk and overhead into your environment.

Learn how VMware ESX/ESXi is—and will continue to be—the industry’s most robust and production-proven hypervisor and why it is a better choice than other hypervisors.

• Comparing Hypervisors
• Why Architecture Matters
• Achieve Scalable Performance
• Why File Systems Matter
• An Ecosystem of Virtualization Security Solutions
• Industry Recognition

Comparing ESXi and Microsoft Hyper-V

VMware ESX/ESXi—the industry’s first x86 “bare-metal” hypervisor—is the most reliable and robust hypervisor. Launched in 2001 and now in its third generation, VMware ESX/ESXi has been production-proven in tens of thousands of customer deployments all over the world. Other hypervisors are still version 1.0 products, unproven in production datacenters and lacking core capabilities needed to deliver the reliability, scalability, and performance that customers require.

So while others try to catch up to VMware in the areas highlighted below, upcoming VMware releases will take ESX/ESXi to the next level of enterprise-class hypervisors—extending our lead further and ensuring that our customers obtain unparalleled levels of performance and reliability.

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Hyper-V, Xen, and KVM: Too much code

When it comes to virtualization, smaller is better. A smaller virtualization footprint reduces the attack surface for external threats and can drastically lower the number of patches required—both result in a more reliable product and a more stable datacenter.

As part of VMware’s ongoing focus to advance virtualization reliability, VMware created VMware ESXi, the industry’s smallest hypervisor and first complete x86/x64 virtualization architecture with no dependence on a general-purpose operating system. No other virtualization platform can match the compact size of VMware ESXi with its small disk footprint of 32 megabytes. It removes all the patches that would normally need to be applied to and the security risks associated with a general purpose server operating system. Microsoft Hyper-V, Xen, and KVM all have architectures that depend on a general purpose server operating system, linking the reliability of their hypervisors to that of the respective general purpose server operating system.

Microsoft attempted to follow VMware’s lead to reduce the attack surface of its virtualization platform by offering Windows Server Core (a subset of Windows Server 2008) as an alternative parent partition to a full Windows Server 2008 install. However, the disk footprint of Server Core in its virtualization role is still approximately 2.6 gigabytes (GB). Until Microsoft changes its virtualization architecture to remove its dependency on Windows, it will remain large and vulnerable to Windows patches, updates, and security breaches. All of the proprietary Xen-based offerings, such as those from Citrix, Oracle, Red Hat, Novell, Virtual Iron, etc., face similar issues by relying upon general purpose Linux as a core part of their virtualization architectures.

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Achieve Better Scalability and Performance in your Data Center

The hypervisor plays a key part in delivering scalable virtualization performance. See detailed performance demonstrations and comparisons in the performance section of our website—the results clearly demonstrate that VMware ESX/ESXi achieves high-performance throughput in a heavily virtualized environment, even as the number of total supported users and virtual machines per physical host increases. Join the discussion on the latest performance topics on VROOM!—VMware’s performance team blog. Recent blog discussions include:

• ESX Runs Java Virtual Machines with Near-Native Performance
• DRS Performance and Best Practices Paper
• Scaling Real-life Web Server Workloads

How fast an ESX can go? 100,000 IOPS and more!

I/O is one of the most critical performance bottlenecks in virtual environments, but even the most I/O-intense application runs fast on VMware ESX. The result is that end users have no idea that their applications are being served from a virtual environment—any latency or overhead is usually imperceptible to the end-user. A recent test conducted by VMware with the EMC Midrange Partner Solution Engineering Team, showed that a single ESX host is capable of driving over 100,000 IOPS, maxing out the throughput of 500 disk drives in a SAN. To put this into perspective, you would need to run 200,000 Microsoft Exchange mailboxes (LoadGen heavy user profile) to generate an I/O rate of 100,000 IOPS. With that kind of performance power available, even your most demanding workloads can be virtualized.

Other vendors have tried to show-off their I/O performance, but their test results have been criticized due to suspect test configurations not based on real world virtualization scenarios. They also unrealistically limit tests to only one or two VMs to avoid their scaling weaknesses.

So then the question arises, why does ESX scale and perform so much better than other vendors’ offerings. There are a number of reasons, as articulated in a recent VMware article, “A Look at Some VMware Infrastructure Architectural Advantages.” Two main reasons are the 1) VMware ESX direct driver model and 2) its more effective management of memory.

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Why File Systems Matter

Virtual machines are fully encapsulated in virtual disk files that are either stored locally on the VMware ESX server or centrally managed using shared SAN, NAS or iSCSI storage. A benefit of shared storage is that it allows virtual machines to be migrated easily across pools of hosts—and VMware Infrastructure 3 simplifies use and management of shared storage with the Virtual Machine File System—VMware vStorage VMFS. With VMware vStorage VMFS, a resource pool of multiple VMware ESX/ESXi servers can concurrently access the same files to boot and run virtual machines, effectively virtualizing the virtual machine storage. The ease of storage management using VMware vStorage VMFS has been a huge financial boon to VMware’s storage partners as it has clearly shown to customers the value proposition of shared storage when virtualizing their datacenters.

While conventional file systems (like Microsoft’s NTFS) allow only one server to have read-write access to the file system at a given time, VMware vStorage VMFS is a high-performance cluster file system that allows multiple VMware ESX servers read-write access to the same virtual machine storage, concurrently.

VMware vStorage VMFS gives VMware Infrastructure 3 a distributed systems orientation that distinguishes it from our competition. VMware DRS and HA features rely on the ability to aggregate the processing, storage and network capacity of multiple hosts into a single pool or cluster upon which virtual machines are provisioned. The VMware vStorage VMFS file system enables this capability. VMware vStorage VMFS allows multiple hosts to share access to the virtual disk files of a virtual machine for VMotion live migrations and rapid restart while managing distributed access to prevent possible corruption. And for times when customers need direct access to capabilities that are specific to their storage array, they can use a raw device mapping (RDM) instead VMware vStorage VMFS for those virtual machines.

Our competition is just now rolling out first-generation hypervisors with a single node orientation. Those products lack the distributed system features like resource pooling, and they rely on conventional clustering for virtual machine mobility and failover. Their clustering technologies are difficult to configure and they require dedicating a LUN to each virtual machine for independent operations, meaning either 1) maintaining one VM per LUN—a management nightmare or 2) if multiple VMs are stored on a single LUN, all those VMs must failover concurrently—neither case is ideal. Our competition advocates purchasing a third-party clustered file system to address this issue, but that introduces more complexity, validation, and cost into your environment.

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An Ecosystem of Virtualization Security Solutions

With VMware VMsafe™, you gain access to a rich ecosystem of third-party security solutions for virtualized environments. VMware is the first and only virtualization vendor to introduce this open security framework that is fully integrated with its virtualization platform.

• Choose from best-of-breed security solutions from all major security vendors, fully integrated with VMware Infrastructure capabilities like VMotion, Storage VMotion, DRS, and HA.
• Get fine-grained visibility over virtual machine resources and monitor every aspect of the execution of the system.
• Stop previously undetectable viruses, rootkits and malware before they can infect a virtualized system.
• Protect your assets better in a virtual environment than you could on physical counterparts with security capabilities not available on physical environments.

As for our competition, they currently do not offer anything comparable.

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Industry Recognition for VMware

The reliability of VMware products and VMware’s overall leadership is being recognized by press and analysts alike.

Among the hundreds of awards given to VMware products over the past several years, one stood out regarding reliability. Redmond Magazine recently awarded VMware ESX the top spot in the “most reliable” category of its 2008 Editors’ Choice Awards for all IT products.

• Redmond Magazine: Most Reliable Category of 2008 Editors' Choice Awards
  “The least stable part of ESX is usually the administrator. The code is virtually bomb-proof.”

Also, a recent Taneja Group report also espoused the reliability of VMware ESX/ESXi:

• Taneja Group: Architectural Requirements for a Datacenter-Ready Virtualization Platform
  “Of all the OS and hardware based virtualization platforms that are currently competing for end user attention and investment, the VMware hypervisor architecture comes the closest to meeting the standards for data center readiness. VMware ESX Server 3i aspires to deliver the reliability, security and performance of native hardware, which makes it a compelling choice for enterprise use.”

Independent press and bloggers are also reporting on VMware’s leadership and advantages:

• eWeek Channel Insider: VARs Choose VMware for Server Virtualization
  “Solution providers say VMware wins by a landslide when it comes to server virtualization…”
• CRN: Partners: Microsoft Still Trailing In Virtualization
  "I don't believe Microsoft will have a true competitor to ESX Server for at least another year, and it will certainly still be missing features which ESX Server has."
• TechTarget blog: VMware superiority doesn't end with its hypervisor
  “…it appears to me that VMware has a pretty good strategy, focus and direction for staying ahead of the competition.”
• Network World: Microsoft a distant third in mock debate on virtualization
  Debate outcome: “VMware’s going to win the virtualization battle, and Microsoft won’t even be its nearest competitor.”

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