Amazon EC2: Between a Rock (Xen) and a Hard Place (Red Hat and KVM)

Is it me or does anyone see the clouds brewing on the horizon (pun intended) regarding Amazon using Xen on RedHat to support EC2 and RedHat declaring KVM as their strategic hypervisor of choice?

Reading Richard Jones' blog on New Year's Resolution for Red Hat, it made me think about EC2, which runs on RHEL and Xen. Here's an excerpt from Richard's blog:

Earlier this year, I blogged about Red Hat’s moves to Kernel Virtual Machine (KVM) from Xen virtualization and dinged them for not being clear with their customers on their roadmap and intentions for their future products and direction.  What will happen with Xen in RHEL6 remains unclear at this point.  Not good for customers, a clear vision is always more welcome compared to a hazy one.

So here’s the first Red Hat New Year’s Resolution:

•    Clearly articulate that Red Hat will deliver RHEL6 as the best Linux virtualized guest operating system.  RHEL6 will not include a Xen kernel.  The Red Hat Embedded Hypervisor distribution based on KVM technologies is the x86 virtualization hypervisor of choice for running RHEL6 and previous RHEL guest operating systems plus other guest operating systems.

A good resolution indeed, but what if you're Amazon?

I know that Xen will be packaged and supported (meaning: able to run) on RHEL for a while, (personally I doubt RedHat will stop packing Xen with its distribution, but that's another story), but it’s the ancillary things that concern me. For example, don’t you think that RedHat will spend far more development resources integrating KVM in their management applications than Xen? What about support? Do you think RedHat will have and maintain the expertise on Xen like they do for KVM? How about high availability and VM live migration? Will RH put the resourcing into making HA and VM live migration a full-featured product in Xen vs. KVM?

If you’re Amazon, what do you do? You’re making good progress (and revenue) from EC2, so you don’t want to “mess with it” too much. But, they have to know that the longer they stay on Xen, the harder the platform becomes to manage and maintain, driving up costs and creating a competitive disadvantage. Does Amazon continue to use RHEL because EC2 uses it now and works well, yet realize that the tools you need to manage and support EC2 means you’ll have to do all of the development yourself? Or, do you switch to SuSe Linux where Xen is considered a strategic direction? At some point, you know Amazon will ask themselves those questions.

Amazon is between a rock and a hard place.

The most likely scenario is Amazon stays put, and RedHat supports them as best as they can for now. But look 3-5 years down the road. What happens when other Infrastructure-as-a-Service providers come online and begin to be cost competitive with EC2? Cloud provider market is going to get competitive. Vendors are going to squeeze dime of cost out of their infrastructure in attempt to lower their overhead, pass the savings on the customer, and create a compelling product. Amazon will eventually be forced to consider this quandary.

What do you think? Like to hear your opinion.

posted by: Drue Reeves

Comments

[Benjamin Schweizer]

It's not that important for Amazon; they have a pretty good team for sure and do not rely on Red Hat therefor. I think they are using RHEL because of everything else (except the hypervisor). So, I don't expect much change soon.

[Drue Reeves]

Hi Ben,

Thank you for the good comment.

Time will tell on this one, but I wouldn't rule out a switch to something similar like XenServer. A radical hypervisor change (like to Hyper-V or ESX) is probably out of the question.

While Amazon has a good team, economic forces (over a longer period of time) tend to change people's mind. We'll see.

[Kristoffer Sheather]

Amazon have the resources to build their own minimal customised distribution using KVM as the hypervisor.

Thats the direction I'd be expecting them to take.

[GR]

We've been using KVM hypervisor for all our VM's and the performance is great. I would expect that Amazon and other clouds will start offering KVM-based services. I believe Rightspace is already offering KVM.

[Gerry]

I think Amazon should support both hypervisors, Xen and KVM. KVM is going to win this battle eventually and Amazon should prepare to migrate.

[Paras Jethwani]

good thread - don't have much to add - time will tell - but this discussion was quite informative

[bmullan]

I initially thought this way also.

But then I realized it wasn't the virtualization technology so much as the API's that AWS has created for a "cloud" engineer such as the already published definitions for ami and api mgmt and the tools that AWS provides or 3rd parties provide based on those published API/AMI "standards"... (boto is a great example!)

Does it really matter if a USER 'ec2-run-instances' command starts a VM under KVM or XEN ?

To the USER ... if the windows or linux etc machine starts and is accessible... it probably doesn't matter except for the cost factors which can include HA, live migration, etc. considerations.

So maybe AWS can migrate users somewhat transparently over xen to kvm?

Or AWS "is" IaaS... they could offer separate xen and kvm based services... maybe use the same api/ami definitions and let users choose their environment based on features, & costs.