How to Choose Between Hyper-V and vSphere

9 October 2013 ID:G00239335
Analyst(s): Thomas J. Bittman

VIEW SUMMARY

Microsoft has improved its server virtualization products to the point that IT leaders should assess their VMware investments and consider whether Microsoft makes sense. Compare acquisition costs, ease of management and functionality for the two vendors and take advantage of their competitiveness.

Overview

Impacts

  • When assessing the latest offerings for server virtualization from Microsoft and VMware, IT leaders face an increasingly competitive and critical choice.

Recommendations

  • Compare acquisition costs, ease of management and richness of functionality to assess how well the two vendors address your requirements.
  • If acquisition cost is your sole acquisition criterion, then Microsoft is a less expensive option for most deployments.
  • Consider VMware for its total cost of ownership (TCO), because it offers an integrated, simplified solution with less planned downtime and fewer operational errors.
  • When functionality richness and broad OS certification are the most important factors, Microsoft matches up well with VMware in most categories; however, evaluate how they compare on the specific functions that are critical to you, rather than on their overall capabilities.

Analysis

Microsoft has been rapidly expanding and improving its server virtualization and virtualization management offerings. A market once dominated by VMware now has two clear leaders, and the marketing has been ramping up accordingly. It's easy to become bogged down in rapidly changing scalability limits and long feature lists; however, there are some clear areas of differentiation that should be considered by all users.

Figure 1. Top Impacts and Recommendations for How to Choose Between Hyper-V and vSphere
Figure 1.Top Impacts and Recommendations for How to Choose Between Hyper-V and vSphere

Source: Gartner (October 2013)

Impacts and Recommendations

When assessing the latest offerings for server virtualization from Microsoft and VMware, IT leaders face an increasingly competitive and critical choice

Microsoft has reduced the competitive gap with VMware's vSphere after delivering Windows Server 2012 and System Center 2012. Which product is appropriate will depend on your existing investments and skills, as well as your organizational priorities. In terms of priorities, there are three major areas of comparison to consider:

  • Acquisition costs
  • Ease of management (including operational complexity and cost)
  • Functionality richness.

Acquisition costs generally favor Microsoft, although it depends on the size of the deployment, whether Microsoft's System Center is needed for a Hyper-V deployment and whether vSphere Enterprise Plus is needed for a VMware deployment. Ease of management favors VMware today, although Microsoft will integrate management functions over time. Functionality richness favors VMware, although it depends on the specific OSs that need to be supported and which features are required.

Acquisition Costs

Due to packaging differences, comparing the cost of Microsoft's virtualization solutions with VMware's is not straightforward. However, there are still some reasonable comparison points.

Small

At the lower-end of the market (one to five hosts), both vendors have "free" offerings, but Hyper-V has the edge (assuming Windows-based guests) with a number of bundled features that might make a big difference. These include Hyper-V Replica, no package scalability limits, cluster-wide switching, live migration and networking virtualization. The freely installable Hyper-V Manager gives you basic management capabilities that are good enough for a small number of hosts (one to five or so, in a single cluster). In fact, because Microsoft's System Center VMM is bundled together with all System Center products in just two editions — Standard and Datacenter — VMM is price-prohibitive in smaller deployments.

VMware's vSphere Essentials Kit (for three hosts) provides a lot of value for a low price (including vCenter Operations Manager), but notably does not include vMotion, high availability or vSphere Replication. Those require Essentials Plus (at 10 times the price of Essentials). However, Essentials Plus also gives you Data Protection for backup, while the Microsoft solution will require System Center for Data Protection.

Medium

As long as System Center is not required, Microsoft is less expensive. However, once the number of hosts and virtual machines (VMs) requires centralized (rather than host-based) management tools, the equation flips. vSphere Standard Edition (plus vCenter Standard) is less expensive than Hyper-V when System Center VMM is required. Granted, vSphere Standard Edition does not include load-balancing tools, such as Distributed Resource Scheduler (DRS) or Storage I/O Control, but for many midsize environments — perhaps up to 10 hosts — Standard is good enough.

Large

However, when requirements demand richer load-balancing and capabilities such as Distributed Switch, vSphere Enterprise Plus is required, and the acquisition cost is roughly double that of Hyper-V and System Center. This includes functionality that Microsoft does not have, such as Storage DRS. As deployments become larger, however, memory management differences may become important. VMware has four mechanisms of proven memory management technologies that can significantly increase VM density and reduce hardware acquisition costs. Microsoft has two mechanisms: dynamic memory, introduced in Windows Server 2008 R2, and smart paging, which is new in Windows Server 2012 (although smart paging is limited to extreme low memory conditions, almost exclusively VM restart). On average, VMware's customers have higher VM densities. This is due partly to memory management, partly to mature DRS capabilities and partly to more mature virtualization deployments.

Bottom Line

For small Windows-based deployments, it's hard to beat free, so Hyper-V wins. For deployments that require more centralized management, VMware is less expensive until functionality and scale requirements push users to VMware's Enterprise and Enterprise Plus. They cost more than Hyper-V with System Center, but this expense is partially mitigated by higher VM densities and lower hardware costs.

Ease of Management

Acquisition costs are important; however, in large deployments, operational expense and ease of management become bigger cost factors.

In general, Microsoft matches up well against VMware in terms of management checkboxes; however, in many cases, Microsoft already had functionality now needed to accommodate virtualization, while VMware designed many tools specifically for managing and automating VMs. Setting up a high-availability (HA) environment is a good example. For VMware, turning on HA is basically a checkbox. For Microsoft, HA is more complicated, and requires the use of multiple tools, including the Failover Cluster Manager, Hyper-V Manager and, for many users, System Center VMM. Another example is that VMware provides simple affinity and anti-affinity management for VMs using DRS. Microsoft can also enable (most) affinity and anti-affinity rules (at least, affinity to hosts), but doing so is complicated, and it requires using cluster management and nonobvious Dynamic Optimization rules.

Hyper-V administrators are forced to use multiple tools. Hyper-V Replica, for example, must be configured in Hyper-V Manager. There are dozens of configuration and diagnostic tasks that can be performed only via PowerShell.

Although Microsoft has rapidly increased the scalability of VMs (it is now leading in many categories), it is still behind in management scalability, which is important with large enterprises and service providers. System Center is limited to managing 25,000 VMs today (APIs are available for service providers to extend beyond this, in System Center 2012 SP1), while VMware's limit is 15,000 per vCenter Server, but 100,000 in linked mode (with vCloud Automation Center).

One continuing concern of Hyper-V customers has been the management of the parent OS. Unlike ESXi, Hyper-V relies on a parent OS to host input/output (I/O) drivers and management agents. A minimal footprint, called Server Core, has a disk footprint of 5GB (a full Windows footprint is 8GB to 10GB). VMware's vSphere has a 144MB footprint. The size of the footprint means that Hyper-V's parent OS is more likely to require patching and, often, forced reboots. This entails more live migrations and operational effort. Microsoft has been investing heavily to reduce the footprint, target patches and reduce the need for reboots; however, this remains a differentiator. VMware's small footprint also makes central management of stateless/diskless hosts (and consistent host configuration management) easier.

Finally, one management challenge has been availability of Hyper-V skills. Similar to challenges facing early adopters of VMware when it was rapidly growing, finding (or creating) experienced skills for Hyper-V and VMM is difficult, especially as Microsoft invests heavily to add new functionality.

Bottom Line

Although Hyper-V and its management tools (including System Center) can perform most of the same functions as vSphere and vCenter, Microsoft's virtualization solution tends to be more complex and easier to break, which increases its corresponding operational costs. Expect Microsoft to continue to invest in ease of management improvements to close this gap, and more skills to become available as the market matures.

Functionality Richness

Microsoft has been investing heavily to catch up to VMware's functionality, and it has made great strides recently. For example, some important additions are coming in Windows Server 2012 R2, such as Storage QoS (although Storage QoS provides only basic boundary condition management versus richer quality of service [QoS] management provided with VMware's Storage I/O Control) and improvements for Linux snapshotting. However, still missing is something comparable to Storage DRS (to automate and balance storage usage, in parallel with DRS for servers), and something comparable to VMware's Site Recovery Manager (SRM) — although this may change soon.

SRM is perhaps the most important functionality gap. Disaster recovery (DR) enablement has been one of the most important drivers for virtualization, with about half of early adopters of virtualization planning to use virtualization for DR. SRM enables the automation of the process of using VM files as the currency of backup and recovery, including the ability to test recovery scenarios. A large percentage of VMware customers (one-quarter or more) use SRM. Microsoft has Hyper-V Replica — introduced with Windows Server 2012 — but that helps at the VM level (and note that VMware has its own "vSphere Replication" capability), whereas SRM focuses more on a site of many VMs (and rich integration with storage arrays for managing large-scale replication). For Gartner clients using SRM, Microsoft is not a consideration yet — or, at least, not without additional third-party DR tools.

However, Microsoft has a preview trial offering of Azure-based Hyper-V Recovery Manager, which could change the equation. To this point, Gartner has received no client feedback on Recovery Manager, but the concept of orchestrating failovers (for testing purposes and for real) from and as a cloud service might change the DR argument between VMware and Microsoft.

Microsoft has a shorter OS compatibility list than VMware, but does certify most major variants, including Windows Server 2003 SP2 and newer, and the latest versions of SUSE Linux Enterprise Server (10 and 11), Red Hat Enterprise Linux (5.5 through 6.3), and CentOS (5.5 through 6.3). However, for those enterprises that have a much broader range of OSs to support, they are likely certified with VMware — such as Solaris, Oracle Linux (Oracle won't certify on vSphere, although it does provide support for its customers running on vSphere), FreeBSD, DOS, NetWare and OS/2, as well as older versions of SUSE, RHEL and CentOS.

On the other hand, because it leverages the Windows driver model, Hyper-V has a much broader hardware compatibility list, especially in terms of a variety of I/O devices. However, the range of I/O devices is a bigger benefit with hardware enthusiasts, rather than enterprises.

Although Hyper-V supports various Linux variants, only a small percentage of customers currently run Linux on Hyper-V (while perhaps 20% to 25% of VMware-based VMs are Linux variants). One of the nagging issues with Hyper-V has been the need to suspend a Linux instance to do a snapshot backup (which is not required for Windows-based VMs). Microsoft has announced that it is changing this with Windows Server 2012 R2.

In terms of independent software vendor (ISV) support, any ISV certified on Windows Server is also certified to Hyper-V. However, Hyper-V is new enough that the ISV expertise on Hyper-V is limited, compared with ISV expertise with vSphere, and many Windows-certified ISVs may not have any customers running on Hyper-V. On the other hand, in June 2013, Oracle announced that it would certify its database, application and middleware software on Hyper-V, which is something it has not done for VMware.

Gartner polls show a rapid growth in private cloud deployments and a strong interest in hybrid cloud scenarios. In most cases, private cloud services are based on provisioning and automating infrastructure and VMs, and, since 2008, more than 40% of larger enterprises have begun deploying something. Again, Microsoft is late to a rapidly growing market opportunity, introducing its first real functionality in a feature-packed System Center 2012. At the same time, Microsoft made several important shifts in its service provider strategy — supporting Hyper-V VMs on Azure (for an infrastructure as a service offering) and promoting cloud enablement with service providers (where previously, Microsoft was positioned only as a competitor with Azure). However, in addition to giving VMware a seven-year head start on growing a VM installed base, Microsoft gave VMware a two-year head start with cloud infrastructure. The result is that VMware has 20 to 30 times the service provider ecosystem for virtualization and cloud computing as Microsoft. At a time when most of the large enterprises polled are planning to pursue hybrid cloud computing in the next few years, Microsoft has an uphill battle to create a service provider ecosystem to match VMware.

On the other hand, it's important to note that VMware's large service provider ecosystem has not translated to a rapid uptake of VMware-based solutions in "the cloud" or to hybrid cloud deployments. Due to the need to accelerate the market, VMware is investing in its own public cloud offering — vCloud Hybrid Service (vCHS). Balancing the need to drive more customer movement to VMware-based cloud offerings and to maintain a large service provider ecosystem (while remaining a service provider) will be a challenge for VMware.

To give Microsoft its due, in Windows Server 2012, Microsoft increased many of its scalability limits so that it temporarily moved ahead of VMware (prior to vSphere 5.5). However, scalability limits are only interesting if they are leveraged. In general, the biggest functionality gap between vSphere and Hyper-V is in actual usage. VMware's seven-year head start has led to broad use in the largest enterprises and in mission-critical workloads. Microsoft's primary growth market to date has been small businesses, or branch offices and stores of larger businesses. Consolidation densities for Hyper-V tend to be smaller than for VMware — not because Hyper-V can't handle higher densities, but simply because the customers acquiring Hyper-V aren't pushing it as hard (and certainly partly due to VMware's high per-processor licensing costs). Gartner also believes that VMware's DRS contributes to higher utilization rates, due to better optimization algorithms than Microsoft's Dynamic Optimization and higher uptake by enterprise customers.

Gartner believes that Hyper-V and VMM have enough capability to have much higher market share than they do today — but overcoming the surface tension of a successful competitor is proving difficult. Microsoft has also been its own worst enemy by delivering a lot of new functionality, but at a relatively slow cadence — in three releases during the past five years. Based on typical enterprise deployment of new, large Windows Server releases, it will take some time before the latest features in Windows Server 2012 have a substantial user base.

Bottom Line

In essentially three releases (Windows Server 2008, Windows Server 2008 R2 and Windows Server 2012), Microsoft has made great strides in virtualization functionality. In many cases, it has closed the gap, although it really depends on enterprise requirements. If the only (or predominant) OS is Windows, if SRM is not being used, and if references can be found with similar requirements and similar applications, Hyper-V is probably good enough from a functionality perspective.

Recommendations:

  • Compare acquisition costs, ease of management and richness of functionality to assess how well the two vendors address your requirements.
  • If acquisition cost is your sole acquisition criterion, then Microsoft is a less expensive option for most deployments.
  • Consider VMware for its TCO, because it offers an integrated, simplified solution with less planned downtime and less room for operational errors.
  • When functionality richness and broad OS certification are the most important factors, Microsoft matches up well with VMware in most categories; however, evaluate how they compare on the specific functions that are critical to you, rather than on their overall capabilities.

Microsoft has been investing heavily to catch up to VMware in terms of functionality, and in most cases it has the right functionality for server virtualization customers. It tends to have lower acquisition costs, except for certain midmarket deployments where the price of System Center makes it more expensive. VMware's ease of management reduces operational costs, and, importantly, it reduces operational mistakes (e.g., how HA environments are set up). This reduces but usually doesn't close the TCO gap with Microsoft at the higher end of the market.

VMware has broader OS reach and functionality (e.g., SRM) than Microsoft, but Microsoft is investing to close these gaps quickly. Enterprises should consider Hyper-V in new deployments and in separately managed topologies in existing VMware customers. When evaluating consultants, demand references that prove skills — don't be a training ground. When evaluating Hyper-V for important roles, demand references with similar requirements. The good news is this market, once dominated by a single vendor with the ability to charge anything it wanted, is now competitive. Take advantage of that.

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