Windows 2012 Hyper-V – the hypervisor for your Cloud? Part III

Windows 2012 Hyper-V is the hypervisor for the cloud. VMware’s vSphere is a dead man walking?

In parts One and Two I shared a chunk of what I learned from Aidan Finn‘s enlightening and entertaining session “Windows Server 2012 Hyper-V & VSphere 5.1 – Death Match” delivered at the E2E Virtulisation Conference in Hamburg.  We’ve considered pricing, scalability and performance, as well as storage  then gone on to consider resource management, security and multi-tenancy and what a flexible infrastructure can give.

Some have found this a useful comparison. Others have highlighted that this isn’t a feature-by-feature comparison and that if it was, the tables would be very different: they would, they’d be longer for a start.  But more importantly, would they give the high view that many are focused on? Is the goal a technical  Top Trump  victory, or alignment to business goals? If aligned, how aligned? A friend used to often quote the difference between cabinet making, carpentry and joinery is effort and measurement: they each had their place, the trick was knowing what level to apply.

In Part III, lets question further Aidan’s premise that Hyper-V kills vSphere. Here we’ll consider High Availability and Resiliency.

High Availability

Capability HyperV(2012) XenServer(6.0) vSphere Hypervisor vSphere(5.1 Ent+)
Incremental Backups Yes Yes1 No Yes
Inbox Replication Yes No2 No


NIC Teaming Yes Yes Yes Yes
Integrated High Availability Yes Yes3 No4 Yes
Guest OS Application Monitoring Yes6 No N/A Yes5
Fail-over Prioritization Yes Yes N/A Yes
Affinity & Anti-Affinity Rules Yes No N/A Yes
Cluster-Aware Updating Yes Yes N/A Yes

1.XenServer 6 provides Automated VM Protection & Recovery in the Advanced edition and higher
2.XenServer 6 provides a Site Replication capability in the Platinum edition, however replication is provided by a storage vendor, not inbox from XenServer hosts.
3.XenServer 6 provides HA in the Advanced edition or higher.
4.The vSphere Hypervisor has no high availability features built in – vSphere 5.1 is required.
5.VMware have made SDKs publicly available, and the appropriate SDK is required to set up customized heartbeats for the applications you want to monitor.
6. If the Guest OS is Windows 2012.

DR is a challenge to enterprises and to the SMEs alike.  It is expensive and it is difficult.  Windows Server 2012 has caught up and surpassed previous versions of Hyper-V.  Windows Server 2012 Hyper-V now supports incremental backup of virtual hard disks while the virtual machine is running, with only the differences backed up reducing backup size and cost.

Guest OS Application Monitoring

Guest OS Application Monitoring allows you to monitor the health of applications running inside the guest operating system of a Hyper-V Virtual Machine. Typically, once you’ve attempted to start a windows service a couple of times you might opt to reboot. However, in a Windows Server 2012 Hyper-V VM you can configure the Windows OS service Control Manager to cause the VM to be restarted: provided that the VM is running Windows 2012. VMware have SDK’s available to allow you to utilize existing APIs – or perhaps you have a service that can make use of this functionality natively.

Hyper-V Replica

A fundamental part of protecting IT is ensuring that the services provided by virtual machines are resilient, and robust at all levels of the compute stack, from hardware through to the application. vSphere has a replication feature that has grown over time to be a feature included in all vSphere editions. It is therefore no surprise that a notable feature of Windows 2012 Hyper-V is Hyper-V Replica (HVR). HVR was designed specifically for branch offices and SMEs that shudder at the expense of a SAN-based or host-based replication solution with their associated expensive bandwidth, indeed Microsoft designed HVR  to work on commercial broadband with no special hardware.  By all means, check out Hyper-V Replica (HVR) in detail.


Capability Hyper-V(2012) XenServer(6.0) vSphere Hypervisor vSphere(5.1 Ent+)
Nodes per Cluster 64 16 N/A2 32
VMs per Cluster 8,000 800-9601 N/A2 4000
Max Size Guest Cluster (iSCSI) 64 Nodes Undoc6 03 16
Max Size Guest Cluster (Fiber) 64 Nodes No 5 5
Max Size Guest Cluster (File Based) 64 Nodes Undoc6 04 03
Guest Clustering with Live Migration Support Yes Undoc6 N/A2 Unsup4
Guest Clustering with Dynamic Memory Support Yes Undoc6 No Unsup5

1.Maximum VMs on a Cluster (Resource Pool) on XenServer 6.0 based on a maximum of 50-60 concurrent protected VMs per host with HA enabled.
2.High Availability/vMotion/Clustering is unavailable in the standalone vSphere Hypervisor
3.VMware does not support VM Guest Clustering using File Based Storage i.e. NFS
4.VMware does not support the vMotion of a VM that is part of a Guest Cluster – although transparent page sharing is still available and usable.
5.VMware does not support the use of Memory Overcommit with a VM that is part of a Guest Cluster – although, again it can be done if properly configured.
6.No XenServer documentation can be found that details the number of simultaneous live migrations over either 1GB or 10GB Ethernet.

Windows 2012 Server Hyper-V failover clusters now supports 64 Nodes. If you’re running as a Hyper-V cluster with highly available VMs, the limit has increased significantly from Windows 2008R2 to 8,000 VMs per cluster and 1,024 VMs per node. This is “unmatched scale” according to Microsoft – VMware’s figures state 4000 VMs per cluster – but we’ve already said, this isn’t about Top Trumps.

VMware offers vSphere Storage Appliance (VSA) software which can be used to create redundant storage out of cheap local hard disks. The software runs on a VM running on the ESXi host. The VSA is now available for free when a vSphere license is purchased. You can find more info on VSA 5.1 here. While great for DIY storage, Microsoft have not used their enhanced storage capabilities to increase the flexibility of their VM clustering. In addition to iSCSI and Fiber, Hyper-V admins have the option of SMB 3.0 file based support. Still cheap does not always mean easy, with Microsoft forum threads querying performance issues being in some instances limited by older hardware.

That said there will undoubtedly be vSphere experts who say Guest clustering can be configured if required – but given the underlying technology is a Guest Cluster all that important any more? There are good reasons on each side for both configurations, clustering in the Hypervisor and Guest Clusters but there is no clear reason to do one over the other yet.

Windows Server Hyper-V 2012 – the Hypervisor for your Private Cloud?

At a cost level, Windows 2012 Hyper-V your private cloud, specifically in a Microsoft Windows VM environment, can be delivered for cheaper than VMware’s VSphere: with equivalent, if not more features and greater clustering scale. Aidan used a picture of The Hulk to suggest all the Hyper-V 2012 features combined to bring a crushing point in terms of you selecting Hyper-V over alternatives. With Hyper-V, any Microsoft edition has the exact same virtualization and fail-over clustering features & scalability. The key market play here is in the increased functionality that Microsoft has introduced.

Still, what about the knowledge and experience of your team? A seasoned VMware shop is unlikely to move en-masse. Licensing may be cheaper, but there is no vExpert trade-in offer. You may well have a skills shift move, a management and infrastructure shift change. At  what cost? For why, and for what benefit? I’m not a fan of introducing a new product because it has more features: I’m a fan of introducing a product that has better features my customer needs. What features do you have in your vSphere environment that have not been addressed by the new Windows Server 2012 Hyper-V release?

Is Hyper-V without fault? Issues with SMB3.0 aside, at the same conference where I heard this presentation there were a number reporting issues with delivering HTML5 websites when running an RDSH session while that session was hosted on Hyper-V: with the suggested solution using . A specific use case for sure but still – hey Emperor, I can see your willy. Still – SR-IOV migration support, Hyper-V replica.. and most importantly – all these features built-in to the core Datacentre license assigned  to the server anyway. In today’s IT environment shouldn’t organisations  be moving to be hypervisor agnostic? Management and automation is key – if you’re wedded to a hypervisor, how flexible are you?

Yet, Aidan will not be alone in considering that there is very little need to move beyond the core Microsoft offering now with 2012. That could translate to cost savings as Windows 2012 Hyper-V has grown up to be a hypervisor for your private cloud, or a wider public service offering. Still, some may argue, although Azure exists as a large Hyper-V implementation, where are the large Hyper-V sites: where is the wide scale adoption? Windows 2012 Server is still quite new:  2008R2 Hyper-V was a pale comparison to the competition. To this extent, Microsoft’s message for Windows 2012 Hyper-V is not just about convincing VMware users to move, but convincing those who discounted Hyper-V as an immature technology that that is no longer the case.

VMware arguably are fighting a rear guard action to the wider public cloud to the likes of Amazon, to Azure. With Windows 2012 Hyper-V Microsoft is looking to attack the extensive underbelly of SMEs not overly concerned with individual nuances of specific features, but instead want a simplicity of deployment and license structure, sensible availability and resiliency options – a lack of complexity at affordable price.

Its a cloud, because it shouldn’t be hard. Windows 2012 Hyper-V for a Windows OS environment, especially a Windows 2012 Windows environment makes IT not hard, but its definitely a more substantial force.