Hyper-V Quick Migration vs. VMWare Live Migration
There has a been a lot of interest in the upcoming RTM of Windows Hypervisor or Hyper-V. One of the big discussions that I have been engaged in, is around VMWare Live Migration versus Hyper-V Quick Migration.There are some ideas that VMotion is superior when it comes to unplanned server downtime. This is simply not the case.
Unplanned server downtime typically is caused by hardware failure which takes the Virtual Servers offline. In the downtime scenario, there it no time for VMotion to move the workloads to the failed server to another operating host. The best thing that can happen in this scenario is that the system automatically boots up the downed VM guests on running hardware. This is the same result with using either VMWare or Windows Hyper-V.
The Microsoft Virtualization Team blog has posted some good information on Hyper-V Quick Migration and VMWare Live Migration. You can read these posts here:
April 20th, 2008 at 5:36 pm
This is true, vMotion is not for un-planned downtime. It is, however, for planned downtime and load balancing. vMotion does the migration with no user interruption, transactional integrity is guaranteed. The most impact you’ll see is one ping time out. With Hyper-V’s quick migration, connections are lost, file copies killed, etc. Try quick migrating a running Exchange Server with thousands of users connected. You might as well have rebooted the server. With vMotion you can migrate that same Exchange Server and no one will be the wiser.
So for planned maintenance and load balancing of production workloads, quick migration isn’t really a solution.
April 27th, 2008 at 7:44 am
Thanks for the post Brian. I am extremely familiar with vmotion as I worked as an administrator at a worldwide company that had nearly the entire data center (nearly 700 servers) running virtualized servers under esx server. My hands on experience with vmotion and esx was a great experience.
However, that being said, in the two years that I worked in that environment I can count on both hands the times we actaully decided to move workloads over during primary production hours using vmotion. For the limited times we used vmotion it was great, but since the Exchnage Servers in the environment where designed to support different shifts and world regions, we could move the Exchange servers over during planned maintenance windows and 98% of the users would have been offline that were on those Exchange servers we were moving. So the impact to thoise users was extremely small. Usnin Exchange 2007, Outlook will auto-reconnect once the mailboxed is moved to another server and the user “might” notice the ‘trying to connect’ status at the bootom of the Outlook window for 30-60 seconds which doesnt even give them enough time to look up the helpdesk number before they are back sending and recieving Outlook updates. So if you plan your work loads properly, their shouldn’t be a huge issue of thousands if users being brought down during a quick migration.
The other great thing about Hyper-V, besides savings an estimated $5,000 per phyical host server, is that when you use System Center to manage the host servers you can manage and monitor from the server hardware level all the way to the application level in a VM. You will also get load analysis with System Center recommending where you can move server workloads to get the best performance. That capability is about 1/5 the cost of esx.
So with good workload planning and performance sizing, you can still use Hyper-V and get 95% (my guess) of the functionality of esx server and save thousands per physical server. If there is unlimited budget, I would go with esx. If there is a budget that needs to be kept and submitted each year, I would strngly consider using Hyper-V and freeing up some dollars spent on virtualization and move them to other areas such as hardware refresh or to stay current on applications that will direcly impact end users productivity.
Look back through may posts about the cost per VM on Hyper-V versus VMWare - using VMWare’s own numbers.
April 27th, 2008 at 7:46 am
better yet. here is the link to the cost comparison: http://www.itedge.net/blog/2008/03/13/vmware-vm-costs-vs-windows-vm-costs/
May 6th, 2008 at 11:41 am
Vmware lists for only $1000 if you don’t get the vmotion. Even without that, you still have VMFS. Windows lacks support for a SAN filesystem, and only offers a failover filesystem on a SAN. That is a big difference even if you want to dismiss the value of vmotion.
If you do not care about a SAN filesystem, Vmware server is free.
May 20th, 2008 at 11:22 pm
Actually Windows Hyper-V does have support for SANs. You can store .vhd (VM guest) files on the local DAS, SAN, or even use the raw SAN disk for a VM and format a partition without having toi use a vhd file.
And why would I want to pay $1000 for VMWare without v-Motion when I will be able to get the Windows Hyper-V built into Windows 2008 at no addtional cost? I don;t think the VMFS is worth $1000, but that what each IT department (with typically shrinking budgets) has to determine for themselves. Personally, if I am going to spend $1000 and not get vMotion, I would rather invest those dollars in other areas (maybe management tools) especially if performance is going to be nearly the same on either system.
Also what does support for VMware cost? If there is already a support agreement with Microsoft in place -which typically makes sense with all the Microsoft software in most companies- that same contract can be used for Hyper-V support. That way additional funding for another support contract doesn’t have to be found.
As far as VMware being ‘free’ if you don’t want a SAN file system… the free verison of vmware server sits on top of a Windows installation just like Microsoft Virtual Server (which is free too). The problem is neither of these are Hypervisor based so they have a lot more limitations and performance will not be as good compared to Hypervisor technologies. Windows Server 2008 Hyper-V (free with Windows Server 2008) is Hypervisor based like ESX Server (not free) is. The increased performance is a must for most production environments.
September 26th, 2008 at 4:21 am
Hi,
Yes I totally agree with this article, that quick migration which is what Microsoft Hyper-V is currently offering lag big time behind VMotion only for planned downtimes, but did you know Microsoft is preparing for live migration and that will be released soon. If that is a surprise for you then what will your face look like seen the hyper v live migration video at Virtualization Team Blog Home Page or of its not there any more at the direct link at Hyper V Live Migration & New Hyper V Server Video
Wow it is not released yet, but it will be coming soon. Check that video out and leave your comment.
Enjoy,
Virtualization master.
September 26th, 2008 at 4:24 am
I am sorry seems the link to the video in my earlier post did not work. The correct link is: http://www.virtualizationteam.com/microsoft/hyper-v/videos-on-the-new-version-of-hyper-v-and-hyper-v-server.html
Enjoy the movie, and I will send you the popcorn.
Enjoy,
Virtualization Master
October 17th, 2008 at 5:04 pm
Thanks for the comment Virtualization Master. I well up to date on the roadmap of Microsoft products. I am limited to what information I can disclose until it is made available by the Product Groups.
The Microsoft sites http://Edge.TechNet.com and http://Channel9.MSDN.com have a lot of the newest product disclosures and videos for public consumption.
Another Microsoft producced video on Hyper-V v2 is here: http://edge.technet.com/Media/Demo-Hyper-V-Server-and-Live-Migration/
Interesting thing is that I actually had seen Live Migration demonstrated live in Hyper-V v1 pre-beta. The feature was pulled until v2 though for the sake of the v1 release timeline.
There are also some other big disclosures being made public at PDC2008 around Windows Server 2008 R2, Windows 7 Client, and Cloud Computing.