Any comparison of Microsoft's Hyper-V versus VMware's vSphere has to take into consideration a number of different factors. First, there's the target customer and the feature set for different sizes of deployments. The needs vary widely depending on the number of virtual machine instances, and these requirements should drive the architecture and configuration choices. Second, there is the topic of management, which is also tied closely to the size of the installation. Beyond these considerations are a number of other issues, including cost, performance, scalability, and usability.
For example, when you install VMware ESXi on a host machine, you have a bare-metal hypervisor that runs independently of any operating system. If you use Windows Server 2012 as the foundation of your virtual infrastructure, you have an operating system that must be patched and updated periodically. That's not to say VMware ESXi doesn't need patches or updates from time to time, but it definitely has a smaller footprint than does Hyper-V.
We'll look at all of these issues and try to compare and contrast the two products from these angles. In the end, the answer depends on all of these factors. The best choice for a small or medium-sized deployment won't necessarily be the same as for a large-scale operation. Other details to consider include corporate culture, existing infrastructure, and history with either of the two products.
Target customerVMware still has the edge when it comes to the high-end, high-volume virtualization customer. VMware features such as the Distributed Resource Scheduler (DRS) address the needs of large environments running large numbers of VMs with varied resource requirements. At the other end of the spectrum, you have to give the nod to Microsoft. If a small-to-medium-size business is purchasing Windows Server 2012 anyway, it doesn't make sense to also purchase VMware's vSphere to virtualize a few specific functions.
The hard-to-answer question is at what point it makes sense to go with VMware. Hyper-V 2012 leverages new capabilities in SMB 3.0 that give even the smallest shops the ability to stand up a high-availability cluster using low-cost servers and commodity SAS disk drives. Hyper-V 2012's host-to-host VM replication provides an additional level of redundancy not previously available from Microsoft and levels the playing field from that perspective.
At the same time, VMware has a similar function that uses the same Microsoft Volume Shadow Copy Service (VSS) under the covers. These and many other similarities make comparing the two products problematic. In the end they are both compelling products with plenty of capabilities that you can tweak to meet most any virtualization need.
Management toolsAt the low end, Microsoft gives you a basic set of tools in Hyper-V Manager, which comes as an installable option with Windows Server 2012. VMware's traditional management tool, the VMware vSphere Client, is a free client you must install on a Windows PC. Both offerings connect to remote hosts, allowing you to manage any system you can reach over the network.
Some functions are not possible in the basic management tools for either product. Advantage here goes to Microsoft as Hyper-V Manager can, for example, export a VM, then do an import to clone or copy the VM. With VMware you must be connected to vCenter Server in order to export or clone a VM. With respect to monitoring, however, the VMware vSphere Client provides much more information about both the host servers and the client VMs. VMware scores a point here for a more detailed graphical presentation.
VMware provides vCenter Server for managing large installations while Microsoft offers System Center 2012. The latest release of vCenter (5.1) adds a Web client to the mix, providing the ability to manage your VMware infrastructure from literally anywhere. Both VMware and Microsoft support automated management using Windows PowerShell. VMware offers a free add-on called PowerCLI that includes a long list of custom PowerShell cmdlets for managing your vSphere infrastructure.
Performance and scalabilityDeciding how to measure performance and scalability presents a challenge when comparing these two products. Microsoft has made a number of enhancements in Hyper-V 2012 that in some cases exceed the outer limits of vSphere. If you want to gauge scalability in terms of raw numbers like nodes supported in a cluster (64 for Hyper-V 2012 vs. 32 for vSphere 5.1) or VMs in a cluster (8,000 for Hyper-V 2012 vs. 4,000 for vSphere 5.1), you would deduce that Microsoft takes that round.
But measuring real-world capacity goes way beyond the basic numbers. Case in point: Both products now support the concept of dynamic memory, albeit in different manners. With Hyper-V 2012, you can configure individual VMs with an initial memory allocation and allow the hypervisor to adjust the amount of memory depending on current needs. This is not the default option when creating a new VM but a configuration setting. VMware has had this feature for several years, and the company claims much more real-world experience in the realm of memory utilization. Advantage here goes to VMware, but Microsoft has narrowed that gap substantially with Hyper-V 2012.
At the individual VM level, I used the Sandra 2013 benchmarking tool to determine basic numbers of performance from a single VM running Windows 7 SP1. This VM was configured to have 2GB of memory and two virtual CPUs. I ran four different benchmarks using Hyper-V 2008, Hyper-V 2012, vSphere 5.0, and vSphere 5.1. You can see from the table that Hyper-V 2012 holds its own against vSphere, at least with respect to running Windows VMs. Note that I did not test performance of Linux VMs. (Tests were run on a Dell PowerEdge R715 with dual AMD Opteron 6380 CPUs, 64GB of memory, and two Seagate ST9300605SS 10K 300GB SAS drives configured as a RAID1 array.)
The bottom lineFinally, one of the most difficult factors to compare is cost. If you're looking at a small number of virtualized servers running Windows Server 2012, you already get that with the purchase of the operating system. Windows Server 2012 Standard comes with two virtual instances, while Windows Server 2012 Datacenter includes an unlimited number of VMs on a single machine. It really doesn't make sense to purchase an additional virtualization product for a small-to-medium deployment.
VMware pricing starts at $4,495 for VMware vSphere Essentials Plus Kit, plus the vSphere Storage Appliance, covering three hosts with two CPUs each. Pricing for the central management system starts at $1,495 for the VMware vCenter Server Foundation, which supports up to three hosts. VMware vCenter Server Standard, which supports an unlimited number of hosts, costs $4,995. VMware vSphere with Operations Management bundles add deeper monitoring and automation capabilities; they start at $1,745 per processor.
Microsoft charges a base price of $882 for Windows Server 2012 Standard and $4,809 for Windows Server 2012 Datacenter for one machine with up to two CPUs. This does not include individual client access licenses (CALs), which are required for each user or device accessing the server, or coverage for additional CPUs. The base price for System Center 2012 is $3,607 for a two-CPU server license and unlimited number of managed operating systems.
Microsoft also has a private cloud offering for customers looking to deploy a minimum of 25 server instances. Called the Cloud Infrastructure Server Suite, it includes System Center 2012 and offers advanced features like self-service workflow, automated provisioning, usage metering, and virtual networks.
Nevertheless, VMware has a number of features for high-end users that Microsoft can't match -- notably the Distributed Resource Scheduler (DRS) and a more advanced virtual switch. DRS is a self-learning automation engine that balances load across both servers and storage devices. The vSphere Distributed Switch includes enhancements such as network health check, backup and restore, rollback and recovery, and LACP (Link Aggregation Control Protocol) support.
Choosing between the two vendors should be relatively easy for the high-end and low-end customers. VMware still wins the big shops, and Microsoft is now the clear choice for the small guys. The fight over the middle has only just begun, and it promises to be an interesting one. Microsoft will no doubt attempt to creep up the ladder while VMware will do everything in its power to keep the castle walls from being breeched.
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This article, "Virtualization showdown: Microsoft Hyper-V 2012 vs. VMware vSphere 5.1," was originally published at InfoWorld.com. Follow the latest developments in virtualization, data center, and cloud computing at InfoWorld.com. For the latest business technology news, follow InfoWorld.com on Twitter.
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