In his three recent articles about Quick Migration and live migration, Jeff Woolsey spends a lot of effort differentiating Quick Migration, VMotion, and VMware HA. Personally, I thought the distinction between these features and the purposes they were intended to serve were pretty clear already, but apparently Microsoft’s earlier claims that Quick Migration and live migration were comparable confused everyone.
The three articles from Jeff can be found here:
Hyper-V Quick Migration and VMware Live Migration, Part 1
Hyper-V Quick Migration and VMware Live Migration, Part 2
Hyper-V Quick Migration and VMware Live Migration, Part 3
In the first article, Jeff discusses the importance of high availability (HA) in virtualization scenarios. He’s absolutely right on target with his statements: HA is critical in virtualization implementations. I couldn’t agree more. VMware recognizes this fact and includes VMware HA, and Microsoft recognizes this fact and provides integration between Hyper-V and Windows Server 2008 Failover Clustering. So far, so good.
In part two, Jeff goes on to state that VMotion doesn’t work for unplanned downtime. Again, he’s absolutely correct: VMotion doesn’t work for unplanned downtime. Then again, apart from the comments that Jeff claims to have received from VMware supporters stating VMotion was “far superior for unplanned host downtime and that it was a much better HA solution”, I don’t think anyone has ever claimed that VMotion was an HA solution. I know I certainly haven’t. I can’t recall VMware ever making that statement. After all, if VMotion were an HA solution, why would VMware have VMware HA? What point would there be in two different HA solutions?
Further in that same article, Jeff compares VMware HA with Windows Server 2008 Failover Clustering, aka Quick Migration, and states that they are comparable technologies. Once again, I agree; VMware HA and Quick Migration are comparable technologies. Both will restart virtual machines on another host automatically in the event of a host failure. OK, Jeff and I still agree thus far.
Part three of Jeff’s series wraps things up by attempting to downplay the importance of VMotion. In his words, “Even customers with Live Migration still wait until off hours to service the hardware.” Unfortunately, this is where Jeff and I have to disagree. I don’t know how many customers they spoke to, but I know I have customers that have live migration functionality who use it during business hours. Besides, live migration isn’t just about hardware servicing or patching the root partition/parent partition/Service Console, it’s also about enabling dynamic load balancing a la VMware DRS, or enabling power savings in off-hours via DPM. After all, just because you can shut down and/or power off guests to migrate them doesn’t mean you will necessarily want to in every instance. It may be acceptable for some workloads, but not for all workloads.
I just can’t help but feeling that if Microsoft hadn’t made the comparisons between VMotion and Quick Migration themselves earlier in Hyper-V’s development, this sort of “unequal comparison” that Jeff is trying so hard to clear up wouldn’t have happened.
Tags: ESX, HyperV, Microsoft, Virtualization, VMotion, VMware, VMwareHA
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Saturday, April 26, 2008 at 9:30 am
Awake
Typical microsoft deception. They do that stuff all the time hoping people are stupid.
If you didnt use Vmotion during the course of a business day you couldnt add hosts to a VMware HA cluster during business hours. Because once the host is added the VM’s would start to muigrate, Live, as it balances resources in the cluster.
We move VM’s all the time with Vmotion during the course of the day. Users don’t even notice. Even if connected to the VM with RDP.
I take any MS says with a grain of salt. They tend to make it up as they go along and dont care if they are right or wrong.
Sunday, April 27, 2008 at 3:25 am
Duncan
It’s just another marketing campaign. I never expected them to compare their technology to vmware’s in a decent way, but this is by far the worst comparison i’ve seen in years.
As if any decent system engineer would wait till the evening to replace defect hardware. Especially when you have an 8:1 consolidation ratio. I don’t think so.
Sunday, April 27, 2008 at 2:36 pm
hot carl
just wanted to agree with you and awake (above) regarding vmotion’ing vm’s during the business day. we do it all the time (.edu w/ ~110k users). it sure beats having to do maintenance after hours, and the users never even know anything is going on.
Wednesday, April 30, 2008 at 8:20 am
Martin
Go VMware fanboys! Ignore all the mud VMware has been slinging at MS now that there’s actual competition in the field…
Wednesday, April 30, 2008 at 10:49 pm
slowe
Martin,
There’s been plenty of mud-slinging from all parties involved, I think.
Wednesday, July 23, 2008 at 5:29 pm
Brandon
I suppose I’m a couple of months late posting on this.
VMware’s DRS with vmotion is amazing technology. I’m not a fanboy, either. We thought about using Hyper-V for dev/qual because.. that is about the only place it makes ANY sense in the enterprise. With 240 VMs we have to worry about a process kicking off and using up a lot of resources on a server. When that happens vmotion with DRS migrates things around and load balances very quickly.
Interesting enough, with Microsoft doing the jig here.. that soon as they have this feature, it’ll be the best thing since sliced bread. With all the bullshit talk, don’t think they’re not working on getting it done too. Its very necessary, except when you don’t have it and are trying to sell something without it.