I never said live migration isn’t useful – I think it’s a powerful technology and I can’t wait for us to have it as well. I just said that it’s not always as straightforward as it sounds. I think you’re also well aware that Microsoft has figured it out (the demos are out there of R2).

Yeah, auto patching isn’t without potential issues, but neither is live migration. If you’ve got an IT shop mature enough to have Vmotion as part of it’s standard processes that, then you’ve probably got an IT shop that is mature enough to auto patch and alert as well. Remember that live migration doesn’t help you when your application fails – so if you’ve got a business critical application you’ve likely got other measures in place to ensure availability (Clustering/load balancing/really expensive synchronisations). You still have to deal with the same issues when patching those as well.

As always, I enjoy the dialog!

Cheers

Stu

Change control is important in an enterprise. I used to work for several large banks and if something came in that was marked emergency then we’d have an emergency change control meeting, get the change approved, and schedule a window. Now companies can make that window happen during the day. Not only does this get things patched sooner/faster (after all this is emergency) it also saves the company money from not having to pay overtime. Should something go wrong you have your full, normal working staff there to take care of it. If you’re doing the auto patch thing at night you have a few problems:

1) You need to spend time scripting the whole process and then finding some node to test the script on. What happens if the process can’t be scripted?

2) When something goes wrong you now have to wait until the appropriate people can be notified, wake up, get some coffee, drive to the office, and finally fix the problem.

VMotion is about freedom and flexibility. It goes beyond just patches. What happens if 100 more people start hitting my app and it needs to move to another host? Do you take downtime to move it with Quick Migration? People are using it a lot at this point. Do you just say sorry, you guys get bad performance until change control approves a move tonight or this weekend? Or do you move it with VMotion and fix the issue right away? Same thing with the storage side and Storage VMotion.

I’m really sorry that Microsoft is the *only* virtualization vendor that hasn’t figured out the simple task of live migration or VMotion. Every other vendor on the planet has it today. Perhaps once you all get it you’ll realize what a true liberator it is for customers and change your mind on its usefulness.

P.S. I work for VMware, but you already know that, Stu.

My fail-back is that VMware’s infrastructure is much more advanced than just “VMotion”. You setup a cluster of 10 hosts. As such you take one host out of production using maintenance mode, update it in that cluster, check the host out and then return it back into service. If it fails you skip it and keep going. A typical well designed cluster can handle at least one failure if not two with no impact to the performance level of the cluster.

In a perfect world every company would have a perfect deployment system. Something to help automate the patch deployment. I personally have had less than ideal experiences using SCMM to deploy patches so I’d use something else. Though the idea is the same.

And if you’re going to do Vmotion during the day, what’s your failback position should a node fail during the patch? Have you been through change control and had a move of your machines approved for daytime? Remember, it only has to go wrong once for you to look bad.

Even though Hyper-V v2 has live migration, I’m still a fan of change control & outage windows, regardless of your hypervisor. I don’t like the possibility of things affecting my users during their working hours.

Cheers

Stu
Disclaimer: I work for Microsoft NZ.