XenSource CTO takes on Oracle's criticisms, discusses virtues of paravirtualization

It was just a couple of days ago that virtualization technology provider XenSource was the target of not one but two rounds of public criticism -- one levied at it by Red Hat, the other by Oracle.  Since I haven't spent any quality time with the folks at XenSource, I thought that now might be a good opportunity to do a podcast interview with the company's chief technology officer and co-founder Simon Crosby.  We didn't get into the Red Hat issue since Red Hat has since retracted its statement. According to The Register, Red Hat said the following as a part of a larger statement in an effort to put the faux pas behind the two companies:

Red Hat is firmly committed to open source virtualization, based on the open source Xen project. We believe the technology from the Xen project is one key component of a virtualization platform which will deliver significant benefits to customers, improving the economics, flexibility, and responsiveness of their IT investments, which we will deliver in the next major release of Red Hat Enterprise Linux. Red Hat is investing agressively in the Xen project and in ensuring its readiness for the enterprise.

Crosby did however suggest that Oracle's comments about the need for a standard way to access virtualization technology is complete nonsense. According to Crosby, in what he described as a technical breaththrough, XenSource and VMware worked through those issues at the recent Ottawa Linux Symposium.  The outcome -- a solution that involves a standard way for operating systems to interface with hypervisors (the layer of software that handles hardware virtualization) -- will work for Microsoft as well by virtue of the relationship that Microsoft and XenSource hammered out with each other earlier this year.

You can download the podcast or use the player at the top of this post to play it back streaming style.  If you're subscribed to the IT Matters series of podcasts, it'll show up automatically on your PC, your MP3 player, or both (depending on how your podcatcher is configured).

Crosby and I covered a lot of ground -- everything from Oracle's comments to any challenges that XenSource has to deal with now that the virtualization technologies from AMD and Intel will be incompatible with each other at the chip level to the licensing revolution that will need to take place as a result of virtualization.  Crosby also spoke at length about a technique called paravirtualization that he believes is the way to go and one that separates XenSource's approach from others.  Here's sampling of Crosby's quotes from the podcast:

• Xen runs very well on laptops.  There are a couple of implementations for the Intel VT Core Duo processors. It runs very happily there. What hasn't emerged quite as rapidly is the market there. VMware has done extremely well as indeed to some extent as Microsoft in the desktop market which is more about developers where the developer is developing for a different platform or they have some complex application, they can have a whole bunch of VMs on a single machine rather than having a whole bunch of hardware.
• The industry has a constant romance with the thin client notion
• The failover, high availability and supportability that [virtualization]introduces is quite profound....in general people are not talking about "higher availability".... I think it will be the next big value proposition for virtualization once its out there and the basic server consolidation message is well-appreciated and the people have bought into this, I think the focus is going to turn onto this in very very big way.
• At some point, somebody has got to stand up and say "Hey Mr. Ellison. I owe you a virtual two-way and not a four-ways worth of CPU license." Now, I don't want to have that conversation with him.  I just want to enable it.
  
• We're simpling enabling users to get back what they paid for... to enable to take advantage of Moore's Law. We've been stuck for some strange reason based on the fact that software and hardware have been initimately tied together. That stalled the availability of Moore's Law to the customer. The stuff that they've been purchasing, they haven't really been getting the benefit of. And now we're going to change that.
  
• Even in the storage world, the number of SAN end-points will change.  So, if I had 50,000 servers and I now have 10,000 servers, that's a smaller number of HBAs but as far as the array vendors are concerned, it's less money. So, across the board, everybody had to rethink what they're going to do from a price perspective.
• We accomodate the differences between Intel and AMD at a sub-architectural level within Xen. Interestingly enough and fortunately enough the Intel engineering groups and the AMD engineering groups sat down and worked with us and designed that interface so there would be commonality so there is no issue whatsoever.
  
• The architecture that Xen innovated is called paravirtualization. Microsoft calls that "englightenment." The key innovation there is that there are tremendous performance, efficiency, and security benefits when the guest is made somewhat aware of the fact that it is virtualized. If the guest knows that it's virtualized, it can collaborate with the hypervisor to achieve far greater performance of memory management, better management of CPU, and I/O.