Choosing a hypervisor has become an increasingly difficult proposition. The technology you choose may depend less on the technical differences between the hypervisor technologies and more on your strategic direction and the type of IT resources you already have in place.
Previously, VMware held a commanding technological lead, but over the years Microsoft has put its might behind Hyper-V and closed the gap, turning Hyper-V into a viable competitor.
VMware and Hyper-V are now technologically comparable, and the differences more or less come down to naming conventions. For example, VMware and Hyper-V have the following high availability features:
|High Availability feature||vSphere 6.5||Hyper-V 2016|
|Live Migration of VMs||vMotion||Live Migration|
|Live Migrations – Automated||Distributed Resource Scheduler||Dynamic Optimization (CPU, mem, disk I/O, Net I/O) and VM Load Balancing|
|Power Management||Distributed Power Management||Power Optimization|
|Storage Migration||Storage vMotion||Live Storage Migration|
In terms of scalability, both Hyper-V and VMware now support maximum configurations available for top level enterprise servers:
|Resource||Hyper-V 2016||vSphere 6.5|
|Host||Virtual CPUs Per Host||2,048||4,096|
|VM||Virtual CPUs Per VM||240||128|
|VM||Memory Per VM||12TB||6128 GB|
|VM||Active VMs Per Host||1,024||1024|
Comparing the two hypervisors on a feature by feature basis doesn’t provide the value it used to because both technologies are more than capable of meeting the demands of most organizations. However each technology has differentiating capabilities that, depending on their importance, may sway you in one direction over the other.
For example, for VMware:
- If you require older or broader guest OS version support then VMware would be the platform of choice. While Hyper-V supports limited Windows platforms (i.e. no Windows 2003) and specific variants of Linux, VMware supports a dizzying array of guest OS platforms
Conversely, for Hyper-V:
- If your servers reside in a colocation facility or you want to protect VMs from a compromised host (i.e. making sure no one walks off with a virtualized domain controller) then Hyper-V’s shielded VMs is compelling. Shielded VMs can only run on an infrastructure you designate as your organization’s fabric and are protected even from compromised administrators.
Hypervisor Management Tools
Hyper-V Manager is the built-in (free) interface that is installed with the Hyper-V role and allows users to manage Hyper-V hosts and the VMs residing on the hosts. The interface allows users to control one host at a time and can also manage hosts that are nodes in a Failover Cluster. Hyper-V Manager capabilities include:
- Configure Hyper-V host wide settings, such as live migrations
- Add/remove/modify VMs
- Add/remove/modify virtual hard disks
- Stop/start/save VMs
- Manage checkpoints
- Control Replication
Failover Cluster Manager (also built-in) manages both the failover of clusters and VMs that have been clustered.
Hyper-V Manager is a relatively simple and lightweight tool, and together with the Failover Cluster Manager, they are more than enough to manage a few servers or a few clusters in a single site.
Deploying virtualization in a small environment is very easy using Hyper-V Manager: simply turn on a role, make sure you have enough disk space, and then deploy. However, Hyper-V Manager does lack important management capabilities necessary for enterprise level environments, not the least of which is providing consolidated command and control of VMs and their accompanying resources across all hosts.
Manageability is an important factor because of the administration and support costs associated with implementing and maintaining a virtual infrastructure. While Hyper-V is free and is included as part of both Standard and Datacenter Editions, its capabilities are limited. If you want a fully capable management tool then you need to purchase the Management Licenses for System Center, because you will need System Center Virtual Machine Manager (SCVMM).
System Center Virtual Machine Manager (SCVMM) sample capabilities include:
- Consolidated management of all VMs (includes Citrix/XenCenter and VMware/vSphere)
- Build VMs based on VM templates for quick deployment
- Hyper-V deployment - (bare metal) unformatted host
- Dynamic Optimization - Analyze VM workloads and move to different hosts using Live Migration
- Power Optimization - consolidate running VMs onto fewer hosts using live migration, then power down the unneeded hosts.
In the simplest of terms, the Hyper-V hypervisor is included in the Windows pricing, but to manage anything more than a basic environment, you will need SCVMM.
vSphere client is similar to Hyper-V Manager in that it allows for the management of VMWare hosts one at a time and can manage both the free ESXi hypervisor as well as vSphere deployments.
- Consolidated management of all VMs
- VM builds based VM templates for quick deployment
- Distributed Resource Scheduler (DRS) - balance resource utilization across hosts in a cluster
- Distributed Power Management - dynamic consolidation of workloads when fewer resources are being utilized. VMs are migrated to fewer hosts and the unneeded hosts are powered off.
The capabilities listed for both SCVMM and vCenter were selected to illustrate the relative parity between the two platforms, and neither list is by any means complete - a Venn diagram of their capabilities would show quite a bit more convergence than divergence.
If both technologies can meet your virtualization needs, and they have comparable management tools - what other factors might come into play to influence your decision?
Hypervisor Management Architecture:
For Hyper-V, SCVMM is part of the suite of products under the Microsoft System Center monolith. The Systems Center suite provides capabilities ranging from configuration management, to backup, to virtual machine management, to more.
For VMware, vCenter provides dedicated central management capabilities for a vSphere deployment and it can be expanded using plugins. vCenter can be quickly deployed as a virtual appliance and provides a streamlined mechanism for managing all vSphere capabilities including host provisioning and configuration management, VM templating and cloning, automated load balancing of VM resources, performance monitoring, storage provisioning and more.
SCVMM can be harder to work with than vCenter, both because virtualization management may take more steps and because of the sheer number of System Center products. However, if you are committed to the Microsoft technology stack and already fluent with other components of System Center, then an implementation of Hyper-V with SCVMM may be a good option.
Both VMware and Microsoft provide excellent support. Whether your organization is making use of Microsoft (Professional or Premier) Support or VMware (Basic or Production) Support you’ll receive the answers you need.
However, if your organization wants to simplify support to a single vendor then Microsoft with Hyper-V can make a compelling case. Having that “single throat to choke” can be advantageous when time is of the essence and the organization simply doesn’t have the resources to triage and broker problems amongst vendors.
Cross Platform Management
If you are operating an environment with multiple hypervisor platforms, then you may be considering ways to collapse the management.
SCVMM integrates with both Citrix Xen and VMware. In order to manage VMware infrastructure you must integrate SCVMM with a vCenter Server. Managing VMware through SCVMM supports quite a few features, including Dynamic Optimization and Power Optimization, Migration, Templates, and more.
In VMware the vCenter Host Gateway feature supports the management of Hyper-V. Compared to SCVMM the functionality is extremely limited, so you will still need to launch SCVMM for anything more than the most basic of capabilities.
If you’re looking for that single pane of glass for multiple hypervisor technologies, SCVMM is the better choice. However, keep in mind that either way you’ll need to install a vCenter Server to manage VMware, and you will need to use SCVMM for most Hyper-V management functions.
Where are you in the virtualization journey?
Let’s focus virtualizing the windows platform. Remember, irrespective of the hypervisor used for virtualization, you will still need to purchase either Windows Standard Edition or Windows Datacenter Edition licenses.
- If you are deploying a new virtualized windows infrastructure or are contemplating a tactical expansion, then the fact that Hyper-V is bundled with Windows Server makes it an appealing option. Hyper-V is especially advantageous if you are a small-to-midsized business (SMB), or are planning to managing only a few servers or a few clusters that are all in one site.
While Windows Server Standard Edition comes with licenses for two Windows server VMs, Windows Server Datacenter Edition includes an unlimited number of Windows server VMs on a single host. If you can manage your Hyper-V environment using only Hyper-V Manager then you can deploy and manage Hyper-V for the cost of only the Windows Licenses.
- If you are already heavily invested in Microsoft technology, and more specifically in the System Center Suite, then there is no incremental cost for SCVMM. Unless you’re already running a vSphere environment with extensive vSphere expertise or need a capability unique to vSphere, sticking with Hyper-V would be the most economic decision.
- If you already have vSphere, then your support and administrators already have extensive experience with vCenter and the management of the vSphere platform. If you’re looking to introduce Hyper-V into your environment, then in addition to considering the differences in licensing costs between SCVMM and vSphere, you will need to consider the amount of time and the cost of the resources needed for IT to learn and implement Hyper-V. Organizations where there is already a heavy investment vSphere competency may find any saving related to Hyper-V licensing quickly negated by the SCVMM learning curve.
- If you are early in the journey, the management platform (SCVMM or vCenter) certainly is impactful in terms of deciding on a hypervisor. vCenter provides a more integrated and intuitive approach to virtualization management, whereas the System Center Suite is a bit more disjointed. Organizations deeply rooted in the Microsoft Technology Stack may feel perfectly at home with the System Center Suite, although many would acknowledge that more steps are required in SCVMM verses vCenter Server.
Microsoft has closely aligned and natively integrated Hyper-V with its popular Azure platform. Azure Site Recovery (ASR) can asynchronously replicate a virtual machine and target an Azure instance as a replica repository. The seamless integration of Hyper-V into Azure means organizations can easily use ASR rather than having to build out a separate DR site. ASR can also protect VMware VMs managed in SCVMM into Azure as disaster recovery option.
Ultimately Microsoft’s paradigm is to reduce friction as it applies to running applications either on premises, in the cloud, or in a hybrid configuration. It is no secret that Microsoft views Hyper-V as a gateway to Azure, and if you’re already using Microsoft’s cloud, then the high level of integration between Azure and Hyper-V sways your virtualization choices toward Hyper-V.
VMware’s offering for DRaaS is vCloud Air, which was originally owned and operated by VMware, but was sold to French cloud provider OVH. While vCloud Air has not achieved the DRaaS success that VMware had hoped for, VMware continues to provide and support the technology, and OVH is building services on the vCloud Air platform.
Similar to ASR, vCloud Air leverages vSphere Replication to provide replication capabilities at the hypervisor level. VMware shops that pair a local VMware infrastructure with vCloud Air can benefit from being able to use the same tools, technologies and skill sets across both environments.
Other vendors provide DRaaS, and while economics are a critical part of the equation, there are other factors to consider, such as whether IT prefers native support, and how many layers of abstraction (both technical and organizational) IT is willing to accept as part of its DRaaS strategy .
Site-to-Site Disaster Recovery
VMware’s Site Recovery Manager (SRM) is an end-to-end disaster recovery orchestration product that automates the full recovery of VMs on replicated storage. The technology has existed since 2008 and is mature and fully featured. For example, operating under the assumption that it is better to throw people overboard than let the boat sink, you can configure a shared recovery site that is also used to host a lower priority development environment. In the event of a disaster, SRM would shut down development VMs at the shared recovery site and startup the recovering production VMs.
SRM provides for designated startup orders and dependency sequences, and provides for testing of the disaster automation and recovery processes. SRM is fully integrated into vCenter and supports both third party storage replication as well as VM to VM replication with vSphere Replication. vSphere Replication is far more cost effective than storage replication and is ideal for less critical VMs.
If you want to make the most effective use of your internal virtual infrastructure without needing to dedicate resources for an otherwise idle hot standby, and if you want granular command and control then VMware makes a compelling story. SRM is priced separately on a per VM basis as Standard and Enterprise Editions.
Azure Site Recovery (ASR), originally released in 2014 as Hyper-V Recovery Manager, handles end-to-end disaster recovery orchestration for Hyper-V, and can also handle VMware as well. ASR relies on SCVMM’s Hyper-V Replica capability, which is similar to vSphere Replication, allowing for the replication of VMs from one server to another and from one cluster to another. ASR provides capabilities similar to SRM, including automating VM protection and recovery testing.
The technology that best fits your disaster recovery goals will depend on your physical environment, the type of storage replication in use, how tightly you want your disaster recovery components integrated, whether you prefer to manage using PowerShell scripts, and more.
A key differentiator is the pricing - ASR is available on a subscription basis with added costs in the event of a failover, while SRM is a fixed cost, but requires additional hardware. ASR holds an advantage if you don’t have the hardware to support SRM, or if you would rather fund your disaster recovery initiative with OPEX rather than CAPEX funding. SRM has the advantage of a known, fixed cost as compared to ASR, as the exact cost from ASR in the event of a failover will depend on the size and scope of the failover.
How much money, time, effort, and knowledge is already invested in your current hypervisor?
The attraction of Hyper-V can be its initial cost, but in evaluating the Total Cost of Ownership, the support and administrative costs to deploy and maintain the virtualized infrastructure and its components also need to be factored in.
VMware possesses a distinct advantage in terms of both the usability as well as a substantial and knowledgeable labor pool from which to draw from.
Microsoft has made a tremendous investment in Hyper-V and is continually improving it. However, one could argue that because VMware's corporate DNA is completely focused on virtualization that it will continue to be the virtualization technology leader, providing a highly functional and easy to administer hypervisor that supports a healthy ecosystems of integrated and easy to use management tools.
The two-hypervisor conundrum
When determining whether to support a multi-hypervisor environment you’ve got to consider whether your goals are tactical or strategic - are you playing the long game or the short game?
At a tactical level (i.e. maybe the addition of development environment), there can be an advantage in terms of cost savings when deploying a second hypervisor. For example, adding Hyper-V to a VMware environment could be considered “no cost”, because Hyper-V is already included in the Windows Server license. It may also be more advantageous to deploy VMware in a Hyper-V environment, especially when comparing Microsoft’s core based licensing for the Systems Center Suite verses VMware’s processor based pricing for vCenter.
Whether the winner is Hyper-V or vSphere is going to be predicated on factors unique to each environment including the hardware configuration (i.e. the number of processors and number of cores) and the management platform that is in place (i.e. SCVMM or vSphere). The “short game” can certainly show saving, especially in CAPEX.
However, at a strategic level one has to consider the long term risks and resource requirements. Maintaining multiple hypervisors adds additional overhead, especially because of the additional assets required to integrate different compute, network, and storage resources. There is also significantly more complexity when managing multiple hypervisors, and that introduces the risk of human error.
One of the biggest economic considerations when evaluating Hyper-V versus VMware is the pricing of SCVMM as compared to the cost of vSphere. A detailed pricing comparison is covered in a subsequent blog post.
At the most basic level the pricing is based on:
- The difference between the incremental costs of the System Center Suite and vSphere. The System Center Suite uses core based pricing, while vSphere remains processor based. VMware provides a wide array of options with its various editions making an apples to apples comparison a bit of a challenge.
- The resources required to implement and maintain the hypervisor(s)
- Virtualizing a relatively small number of servers and hosts? Then Hyper-V may hold a distinct advantage, if you can manage your virtualization with just the free Hyper-V Manager. VMware does make a free version of ESXi available, however in addition to its technical limitations there is no support.
- Growing out your environment? Virtualizing with vCenter Server, in general, requires less steps and is quicker than the System Center Suite, resulting in a lower TCO.
- Heavily invested in the Microsoft Technology Stack? If the organization has an Enterprise Agreement in place and is already leveraging parts of the System Center Suite for management, then a move to Hyper-V and SCVMM may be more cost effective.
Is there are clear winner? Not really, as both hypervisors offer distinct advantages in their own right and that is good news for the marketplace!
Want to learn more?
Download our vSphere vs Hyper-V comparison matrix - both technologies can provide redundancies that will maximize your uptime and that will allow you to squeeze out the most performance. Which is better and how do you decide?