Live Migration vs. Quick Migration

So there’s been a flurry of coverage over the last couple of weeks regarding a statement from Microsoft regarding WSV’s lack of live migration (aka VMotion) functionality.  As I mentioned when I discussed the announcement of features being cut from Windows Server Virtualization (WSV, or “Viridian”), the lack of live migration functionality really is, in my opinion, a serious stumbling block for Microsoft.  I wasn’t the only one that thought so, either.  (There was a post about it on the VMTN Blog at some point as well, but I can’t find a link for it now.)

After Microsoft announced that live migration wasn’t going to make it into WSV and virtualization-savvy users responded with numerous statements about how this killed WSV’s chances against VI3, Microsoft apparently realized that live migration was, in fact, important to customers.  (Apparently customers don’t like downtime.  Who knew?)

To help alleviate the bad press over the lack of live migration in a product that is already pretty far behind the competition, Microsoft now started spewing stuff about quick migration:

“The recent press has been inaccurate to say we don’t do migration - we do migration: quick migration,” Lees said Wednesday. Live migration is a memory-to-memory system while quick migration is machine-to-machine and disc-to-disc.

Mr. Andy Lees (speaking in the quote above taken from this article from The Register) goes on further to say:

Lees called the debate between quick migration and live migration a “red herring” based on six seconds of difference, which mattered only to disaster recovery. On that basis, Windows Server 2008’s planned geo-clustering feature would help users out of any squeeze and could - he claimed - beat VMware.

Yes, but it’s still downtime, Mr. Lees!  That’s the point—without live migration, any migration solution still involves downtime, and therefore can’t really compete with VMotion.  Host-level clustering is great, and something I’d love to see VMware tackle for those shops where VMware HA just isn’t quite enough to meet SLAs.  But host-level clustering is no substitution for VMotion.

Even this blog posting (from an MS employee, no less) admits that Quick Migration is really nothing more than Host Clustering.  This isn’t new technology; this is just Microsoft repackaging the same old stuff again.  (Unless memory serves me incorrectly, Microsoft has been talking about clustering hosts for a while now.)

Microsoft can change the names of features to make them look more like their competition, but the fact of the matter remains:  when Windows Server Virtualization debuts in late 2008 (supposedly within 180 days of the release of Windows Server 2008, which is due to be released in late February 2008), it still won’t have a feature set comparable to the feature set that VMware has today.

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  1. korman’s avatar

    In our lab we have 7 hosts attached to EMC Clariion storage with 135 VMs and workloads which are very random. We use DRS set to “Fully Automated”. Being that DRS is dependent on vmotion, without either of these features I would guess (have not run without them) we would be plagued with performance complaints and would have had to move many VMs to a Physical platforms. In my opinion VMotion and DRS are vital to a successful virtual platform implementation and I would discourage against virtualizing with any solution that does not have comparable features.

    Greg K
    Senior Server / Storage Engineer

  2. slowe’s avatar

    Greg K,

    From the wording in my original post, it’s pretty clear I agree with you, but it’s nice to see some real-world customers backing me up based on their experiences with the product and its capabilities. Thanks for reading and commenting!

  3. Virtualization Master’s avatar

    Hi,

    I believe arguments between Quick migration and VMotion were very interesting, but its about the time to shift these arguments to discuss the upcoming hyper-v Live migration. Yes, its almost there. Check out http://www.virtualizationteam.com/microsoft/hyper-v/videos-on-the-new-version-of-hyper-v-and-hyper-v-server.html to find out a video of the new hyper-v Live migration. In addition, they had further more showed the different between the existing quick migration and the upcoming live migration. I thought it was definitely worth sharing.

    Enjoy,
    Virtualization Master

  4. slowe’s avatar

    Virtualization Master,

    Given that live migration is a feature slated to be in Windows Server 2008 R2 and that release is slated for 2010, I would disagree that it’s “almost there”. On the roadmap? Yes. Almost there? No. And yes, when live migration for Hyper-V does appear, then you are absolutely correct–this discussion won’t be valid any longer. At that point, you will be able to (correctly) compare Quick Migration vs. VMware HA and live migration vs. VMotion.