Virtualization Technology News and Information
The Many Faces of Virtualization

An interesting post on Sun's Blog site coming from Marc Hamilton.

Sun today made available for free download our Logical Domains (LDoms) software for server virtualization on UltraSPARC T1 based servers including the Sun Fire SPARC Enterprise T1000 and T2000 servers. Server virtualization is nothing new although recently we have seen an ever growing explosion in the alphabet soup of virtualization technologies. IBM's LPARs (Logical Partitions) were introduced on mainframes decades years ago while Sun introduced the first open systems virtualization technology 10 years ago with E10000 domains. Two years ago, Sun introduced Solaris Containers, one of the first virtualization technologies you can run not only on Sun's SPARC and x64 servers, but also on x64 servers from IBM, HP, Dell, and others. In fact, the latest Solaris Hardware Compatatibility List on BigAdmin lists 876 systems that run Solaris, including over 800 x86/x64 systems. You can download Solaris for free or order a free Solaris DVD with free shipping to try out Solaris Containers for yourself. In the Microsoft world, VMware is one of the big players, as is Microsoft itself with their virtual server software. Last but not least, with a shortage of "V" names, the open source world is busy developing the Xen project, through many efforts including the OpenSolaris Community for Xen

So why is everyone so interested in virtualization? In short, virtualization allows you to reduce cost and complexity in your data center by using today's ever more powerful servers more efficiently. As servers grow more and more powerful, many applications are simply overserved by the capacity and capability of even a low cost rack mount server like Sun's x2200 (which by the way, during Sun's two week 25 year anniversary sale can be purchased for as little as $1245). The x2200 takes up 1 rack unit (about 1.8 inches) of space in a standard 19 inch computer room rack and can be configured with up to 4 AMD x64 processor cores. So if last year you bought four similar servers, for four separate applications, each with 1 AMD processor core, and your processing needs have only grown 10 or 20%, you can probably replace those four servers with a single server today. Or, you could buy Sun's T1000 server with 8 processor cores (yes, also part of our anniversary sale with configs starting at $2535). At first glance, that isn't a bad deal, get twice as many processor cores for about twice the price. There are a few differences, however, that can make the T1000 a much better value. Each of the T1000's processor cores runs at a slower clock rate that the AMD processors in the x2200. While we have all become accustomed to "faster is better" with respect to CPU speeds, the truth is many applications only use a fraction of a computer's processing capability and are for all practical purposes insensitive to clock speeds. In addition, the UltraSPARC T1 processor in the T1000 can run 4 threads in parallel on each core, so the T1000 can actually run up to 32 threads in parallel, versus 4 threads for the x2200, giving you 2x or more better price performance on the T1000.

But back to virtualization. Why do you need it? Some applications don't. If you are running a busy web server processing 1000's of requests a minute, you probably don't need virtualization. Virtually all web servers (no pun intended) are multithreaded, that means they can process multiple requests at the same time, and utilize all four cores of the x2200 or all 32 threads of the T1000 at once. However, many applications are not multithreaded, and worse, are designed in such a way that they can't co-exist with another application running on the same operating system. Enter virtualization, which lets you run more than one operating system on the same server. Technologies like Solaris Containers can support 100's of Solaris OS containers on a single server (as demonstrated at the Clingan Zone). Xen and VMware even let you run different types of operating systems, say Solaris, Linux, and Windows, all on the same server. I don't have time here to go through all the various combinations of virtualization technology that Sun offers, but we do offer complimentary two day workshops to our customers. If you are running Google's web page and need to serve up 1000's of requests per second on each server, you may not need virtualization, but if you are running a web site hosting service and want to run 100's of different web sites on the same server, giving each customer the flexibility to have root access to their "server" without allowing them to interfere with other customer's, Solaris Containers is a perfect virtualization technology. Sun can help you figure it out.

One final note, not that I like to whine, especially not about trademarks. Many companies these days, including Sun, support open source projects while also building their business around supporting commercial software based on the same open source code. Linux is a good example. Take Ubuntu perhaps one of the most "open" Linux companies. They* sell a great $2750/year server support contract for Ubuntu which is a great deal for companies that are using Ubuntu and want commercial support. If you act fast, Sun's similar Solaris Premium Support can be purchased for $1080/year, although in fairness to Ubuntu our anniversary sale price for a 4 or 8 socket x64 server like the x4600 is higher (but still less than Ubuntu). XenSource has a similar relationship with Xen. XenSource both leads the Xen community and also has their own commercial version, XenEnterprise. Xen, XenSource, and XenEnterprise are all registered trademarks of XenSource Inc. At Sun, we spend a lot of effort contributing to open source communities (Sun is actually one of the largest contributors to Linux through projects like and, and many, many others) and also protecting our trademarks (like our current efforts to reclaim the domain name). There is no contradiction between open source and trademarks. However, as I write, Sun and XenSource are having, lets call it, some interesting conversations around use of the Xen trademark. Some Linux companies have decided not to bother, and simply taken the Xen source code and used it in their product without calling it Xen. That is perfectly legal per Xen's open source license, as long as you don't call it Xen. Sun just doesn't think that is good for the Xen community. Sun would love to be able to call our implementation of the Xen open source code Xen to increase Xen's brand awareness and we are trying to work with XenSource to come up with Xen API test suites and other ways for XenSource Inc. to control their trademarks. We actually have a lot of experience in this area. Hopefully I will be back soon to report some positive resolution to these "interesting discussions".

* Yes, I know that the commercial distribution and support of Ubuntu comes from a company called Canonical, this is easy to tell from the Ubuntu web site.

Read or post a comment on the original, here.

Published Sunday, April 29, 2007 10:07 AM by David Marshall
There are no comments for this post.
To post a comment, you must be a registered user. Registration is free and easy! Sign up now!
<April 2007>