Virtualization optimize

Microsoft's Hyper-V R2 vs. VMware's vSphere: A feature comparison

VMware and Microsoft are ramping up their virtualization games with relatively new releases. Scott Lowe compares and contrasts some of the major features in vSphere and Hyper-V R2.

Microsoft was late to the virtualization game, but the company has made gains against its primary competitor in the virtualization marketplace, VMware. In recent months, both companies released major updates to their respective hypervisors: Microsoft's Hyper-V R2 and VMware's vSphere. In this look at the hypervisor products from both companies, I'll compare and contrast some of the products' more common features and capabilities. I do not, however, make recommendations about which product might be right for your organization.

Table A compares items in four editions of vSphere and three available editions of Hyper-V R2. Below the table, I explain each of the comparison items. (Product note: With the release of vSphere, VMware has released an Enterprise Plus edition of its hypervisor product. Enterprise Plus provides an expanded set of capabilities that were not present in older product versions. Customers have to upgrade from Enterprise to Enterprise Plus in order to obtain these capabilities.) Table A

Click the image to enlarge.
Max host processors. Indicates the number of physical host processors that can be recognized by the system. Bear in mind that the Windows columns are Windows limits and not necessarily Hyper-V limits. Max cores/processor. How many processor cores per physical processor are recognized? Max virtual SMP. In an individual virtual machine, this indicates the maximum number of supported virtual processors. Note: This is a maximum value; not every guest operating system can support the maximum number of virtual processors. Max host RAM (GB). The maximum amount of RAM recognized by the hypervisor. Max RAM/vm. The maximum amount of RAM that can be allocated to an individual virtual machine. Failover nodes. The maximum number of physical hosts that can be clustered together. N/A indicates that failover clustering is not supported for that particular hypervisor edition. Memory overcommit. Does the hypervisor support memory overcommit? Memory overcommitment is a technique available in vSphere that allows administrators to allocate more RAM to virtual machines than is physically available in the host. There are numerous pro and con articles about this topic, but it's clear that having the ability to allocate more resources than are physically available increases overall virtual machine density. The decision to use memory overcommit in a production environment is up to each organization. That said, in my opinion, when used in the right circumstances, I can see great benefit in this feature. Transparent page sharing. Transparent page sharing is one method by which memory overcommitment is achieved. With this technique, common code shared between virtual machines is, itself, virtualized. Let's say that you have 100 virtual machines running Windows XP for VDI. Using transparent page sharing, RAM isn't necessarily a major limiting factor when it comes to desktop density on the server. VMware has an excellent example of this technique in action. Live Migration/VMotion. The ability for the hypervisor to migrate virtual machines between host servers without significant downtime. This is considered one of the most significant availability benefits provided by virtualization solutions. Simultaneous Live Migration. Can the product utilize its Live Migration capabilities to move multiple virtual machines simultaneously between nodes? Live guests per host. The number of virtual machines that can be powered on for a maxed-out host. In the real world, I'd be extraordinarily surprised to see anyone getting close to these limits. Virtualization is a great way to lower costs, but there are limits. Live guests/HA cluster node. If you're running your hypervisor in a cluster, this is the maximum number of virtual machines that can be active on any single host in the cluster. For vSphere with update 1, if you have eight or fewer cluster hosts, you can run up to 160 VMs per host. With nine or more cluster hosts, that number drops to 40. Distributed Resource Scheduler. DRS is a technology that enables the migration of virtual machines between hosts based on business rules. This can be a boon for organizations with strict SLAs. Snapshots per VM. The maximum number of snapshots that can be taken of an individual virtual machine. A snapshot is a point-in-time image of a virtual machine that can be used as part of a backup and recovery mechanism. I find snapshots incredibly useful, particularly on the workstation side of the equation, where a lot of "playing" takes place. Thin Provisioning. One decision that has to be made early on in the life of any server (virtual or physical) is how much storage to allocate to the system. Too much storage and you waste valuable disk space -- too little storage and services crash. In order to maintain reliable services, most IT shops overprovision storage to make sure that it doesn't run out; but that conservatism adds up over time. Imagine if you have 100 VMs all with 4 or 5 GB of "wiggle room" going unused. With thin provisioning, you can have the best of both worlds. You can provision enough disk space to meet your comfort level, but under the hood, the hypervisor won't allocate it all. As space begins to run low, the hypervisor will make more space available up to the maximum volume size. Although thin provisioning shouldn't be used for massive workloads, it can be a huge boon to organizations that want conservatism without breaking the bank. Storage Live Migration. This feature enables the live migration of a virtual machine's disk files between storage arrays and adds an additional level of availability potential to a virtual environment. Distributed Switch. VMware and Microsoft have virtual switches in their products, but only VMware has taken it one step further with the introduction of vSphere Enterprise Plus' Distributed Switch. According to VMware, "Distributed Switch maintains network runtime state for VMs as they move across multiple hosts, enabling inline monitoring and centralized firewall services. It provides a framework for monitoring and maintaining the security of virtual machines as they move from physical server to physical server and enables the use of third party virtual switches such as the Cisco Nexus 1000V to extend familiar physical network features and controls to virtual networks." In short, this new capability increases VMware's availability and security capabilities. Direct I/O. The ability for a virtual machine to bypass the hypervisor layer and directly access a physical I/O hardware device. There is limited support for this capability in vSphere; the product supports direct I/O operations to a few storage and networking controllers. Called VMDirectPath I/O, this feature can improve overall performance since it eliminates the "virtualization penalty" that can take place when hardware access is run through the hypervisor. There are some major disadvantages to VMDirectPath; for example, VMotion can't work anymore because of the hardware need. (Note: This feature is different than direct access to disks, which Hyper-V does support.) Max. partition size (TB). What is the largest partition supported by the hypervisor? Although VHD-based volumes, such as those used by Hyper-V R2, can be up to 2 TB in size, read this blog by Brian Henderson for insight into maximum Windows partition sizes, particularly if you bypass the VHD option altogether and use disks directly. Application firewall (vShield). According to VMware "VMware vShield Zones enables you to monitor, log and block inter-VM traffic within an ESX host or between hosts in a cluster, without having to divert traffic externally through static physical chokepoints. You can bridge, firewall, or isolate virtual machine between multiple zones defined by your logical organizational and trust boundaries. Both allowed and blocked activities are logged and can be graphed or analyzed to a fine-grained level." In other words, you don't need to run traffic through external switches and routers to protect applications from one another. Virtual instance rights. This is a Microsoft-only right that can seriously lower the overall cost of running Hyper-V R2 in a Windows-only environment. If you use the Data Center edition of Windows, you can run as many Windows Server-based virtual machines as you like without incurring additional sever licensing costs. Hypervisor licensing. The method by which the product is licensed. Either per host or per processor.

My school's hypervisor of choice

At Westminster College, we continue to run VMware for its virtualization services. Why? Mainly because it's tried and true. That said, budget pressure forces us to constantly reevaluate services and priorities. VMware's total cost is beginning to become more of an issue. As Microsoft continues to improve Hyper-V R2, we will monitor its progress to determine if and when it might be able to replace VMware, although a possible investment in VMware's VDI product might lock us into VMware for the long haul.

I like VMware's memory overcommitment capabilities and believe that, if used right, the feature can be a boon when it comes to density, particularly as we look at virtualizing desktop computers. On the other hand, for very Microsoft-centric organizations, Hyper-V R2 makes Microsoft's hypervisor offering extremely compelling.

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About

Since 1994, Scott Lowe has been providing technology solutions to a variety of organizations. After spending 10 years in multiple CIO roles, Scott is now an independent consultant, blogger, author, owner of The 1610 Group, and a Senior IT Executive w...

23 comments
DigitAL3X
DigitAL3X

I would love to see and update comparison that looks at vmware 5 and Microsoft hyperv r2 also comparing license differences would be great. Alex

jakson0100
jakson0100

Wow great test, I'm a noob in VM, I only use virtual box for have some windows in my ubuntu computer and Openvz containers with proxmox for a dedicated server and some vps. Chould be a great comparation, http://www.techrepublic.com and http://www.hypervhd.com are very good source for hyperv

Kennymckay
Kennymckay

Interesting how long we've been going on about this now without either MS nor Citrix capturing much of the creamy share of the pie, rather than the pieces most don't really want. However, given the recent announcements this is very relevant again. Combine the SCVMM 2012 announcements with the badly timed vRAM based licensing of vSphere and you have the perfect breeding ground for people considering alternatives... Best comparison site I've actually seen on this so far is http://www.virtualizationmatrix.com although the guy should really include oraclevm and KVM in it (even if niche) K.

jahncm
jahncm

Maybe it is about time to do another eval. I used to be a die hard VMWare fan and I am a VCP, but Windows 2008 R2 SP1 has added improvements we just can't ignore anymore. Since most Enterprises that would be looking to implement either solution for DataCenters (or remote locations) are already licensed for Windows through an Enterprise Agreement, there really is no additional cost to just use what you're licensed for. And the latest updates put the System Center VMM and Hosts at a level where we just can't ignore the roughly additional $3000 price tag per proc (or $12000 per 4 proc server x 2 = $24000,if you want clustering, Live Migration, etc.) Nevermind a datacenter where you have hundreds of Servers. This immediately makes Hyper-V desirable. But also consider NUMA and remoteFX were added and the performance is darn near on par...I gotta say, this may be setting the stage for fierce competition and a reason to replace very, very expensive software. The argument of running more machines on hardware per $ would never be done in a worthwhile production environment to reap the theoretical #s boasted by either parties. When it comes to cost and real world performance and needs, you will probably find 90% can be done now in Hyper-V and SCVMM. Well Done MS!

markw
markw

Good comparison that gets close to comparing apples with apples - some comparisons I've seen try to compare the whole VMware virtual infrastructure (old term I know) with a hypervisor on the other side. However there is a mistake: virtual instance rights are not Microsoft-only: Windows Server Enterprise and Datacenter Edition licenses can also be applied to hosts running other hypervisors to acheive the same licensing benefits around virtualised Windows Server instances: see http://blogs.technet.com/mattmcspirit/archive/2008/11/13/licensing-windows-server-in-a-virtual-environment.aspx

erick_co
erick_co

Yeah, this products are very interesting, but you've forgotten someone else.. Xen? hypervisor. The powerful open source industry standard for virtualization, offers a powerful, efficient, and secure feature set for virtualization of x86, x86_64, IA64, ARM, and other CPU architectures. It supports a wide range of guest operating systems including Windows?, Linux?, Solaris?, and various versions of the BSD operating systems. http://www.xen.org/ Then, why buying an expensive virtualization application when there is another one, open source and free to install?

merton
merton

I do not understand the pricing. Hyper V is free, of course you need to buy a server licence as you do for VMWare. This is a very bad comparison

brian
brian

There are a lot of options available in VMware that you have left out. While I firmly believe both Hyper-V and VMware has their place, I think any fair comparison has to show the available features that Hyper-V simply doesn't have.

azzolin.gustavo
azzolin.gustavo

I havent seen the Fault Tolerance criteria. As I understand it is a very appealing feature that is present at vshere but not at Hyper-V

blu_vg
blu_vg

A couple points to throw out there: 1) If you run Windows as a guest OS, you already get one or more (unlimited with DC) Windows licenses for running as a VM with all the Hyper-V options listed above. With VMware, you still have to pay for those licenses, which are not represented in the costs listed on the chart. 2) Hyper-V Server 2008 R2 (not mentioned in the chart) is free (a comparison with ESXi would be worthwhile, perhaps...), and it includes Live Migration and other features.

garywong0224
garywong0224

Thanks for your posting and I give me a whole look for these two products. a question i like to rise here for Virtual instance rights: for MS, it is 1+4 for enterpise for any virtualization usage. not just in hyper-V. am I true? Thanks Gary

Zarafa
Zarafa

Hello Scott- It's nice to see the vSphere and Hyper-V R2 capabilities listed side-by-side. However, you have at least one fairly-important feature missing: supported storage options. A clustered instance of Hyper-V R2 supports (I believe) Fibre Channel or iSCSI; vSphere supports both of those, plus NFS. Their NFS support is such that there's no discernable difference in performance between that and iSCSI (see various online papers about that). Also, NFS offers some advantages, including the ability to support datastores >2TB (my installation isn't even very big, and we have an NFS datastore about 4TB in size for one of our clusters, and are about to grow that to 10TB soon). Additionally, NFS datasores can be grown dynamically, assuming the storage platform supports such a thing, so getting a bigger datastore doesn't even mean any downtime. Again, great job with the chart and article.

3kl
3kl

I would strongly encourage you to look into the Citrix XenServer platform. The price level is similar to Hyper-V and offers a vast majority of the features in VMware's ESX line. It also offers several features over and above the VMware offering at no additional cost. I also encourage you once again to look at VDI offerings beyond VMware's View product. Other vendors such as Quest and Citrix do not have the hypervisor lock-in that comes with VMware product.

Chas4
Chas4

While I like the current state of Hyper-V, the one issue that will stop me from deploying it is the way that various system keystrokes are handled. The Windows + keys are not passed to the client OS at all. So you have to use the mouse to control everything. In VMWare, once the client has focus, all Win+ keystrokes such as Win+E are executed on the client OS. How MS could have missed this one I don't know.

dwdino
dwdino

The Xen that loses NICs? The Xen that erases LUNs? The Xen that is slow in HA performance? The Xen that continually fails stress tests? Surely, you are not asking to compare it to VMware...

mmcever
mmcever

Support is something else to consider as well with VMware it pretty much doubles the price I have no clue on the cost of support with microsoft, anyone?

Scott Lowe
Scott Lowe

Gary, You'll probably be interested in the follow up to this article that I'm almost done with and that should be going up tonight or Tuesday morning. From everything I've read, you CAN apply a Windows Enterprise or DC license to a VMware server and get the same virtualization benefits that are provided by through the virtualized instances allowed by the licenses. So, the short answer to your question is yes! Scott

Scott Lowe
Scott Lowe

Thank you very much for the kind words and comment! I actually intentionally left that off, perhaps mistakenly. Honestly, I didn't see inclusion of NFS as a particular asset. Are there a lot of organizations out there doing that? It would definitely be a good topic for a follow up article if there are! Again, I appreciate the comments; half the reason I write this stuff is because I learn so much from the community! Scot

Zarafa
Zarafa

I don't have much in the way of real statistics, but from a session I attended at VMWorld on NFS storage, it seems to be fairly popular with customers, particularly from ease- (and cost-) of-implementation perspectives. As far as performance goes, there are papers like this one that show NFS is actually a little better than iSCSI in some cases (and in others not quite as good): http://www.vmware.com/files/pdf/vsphere_perf_exchange-storage-protocols.pdf Results will obviously vary according to specific backend filer, application being tested, etc.

blu_vg
blu_vg

No NFS, but you can do the same in Hyper-V by putting the VHDs on an SMB/CIFS share. You can also perform Live Migration with this feature (iSCSI/FC not required).

mooky
mooky

I work for a very large social networking site and we started out with iSCSI. We now have ~50 ESX hosts and ~1500 guests. We have migrated to NFS (after VMWare started supporting all the other software features such as SRM)and love it. We are now moving to 10 gig NFS. Memory overcommit is huge when it comes to density for us. We are a large microsoft shop and understand the TCO of Hyper-V may seem great at first, but they simply dont offer the flexibility of storage options and dont (yet) offer any enhanced features like SRM for DR/BCP/Moving DataCenters as of yet unfortunately. Storage VMotion is another huge win for VMWare over Hyper-V. The management of VM's with VMWare seems to outshine M$'s current product offerings when you have a large VM infrastructure in my opinion. It definitely is costly though so Microsoft's competetive product offerings/pricing are always a good thing in my book :)