is useful when I want a client machine to be my desktop for now, but afterward I never want to use it again.
One place you might use this is where you want zero footprint. This would include cases where what you have is known to be good but you want to run it on an environment known to be suspect, such as at an airport kiosk or on people’s home machines. CREEGER Looking at the example that Simon [Crosby] suggested earlier, can we define sessions in desktop environments so that at some point you can throw everything away and reauthorize the session with a completely blank slate? Wouldn’t that solve a lot of security issues? BISHOP Yes, but not independent of the application. CROSBY The key question is whether the virtual hard disk itself is stateful or not. Where does the state that I want to keep live? Is it part of the thing that boots? GUSTAV Is it persistent state, or is it transitory/disposable state? CROSBY Where does my persistent state live, and where does the transient state live? CREEGER You have to define session, and that’s a hard thing to do. BISHOP Because it varies from application to application. CROSBY And from user category to user category. In my world, I have VMs on my laptop, and each of my VMs is independently snapshotted and stored in S3 (Amazon’s Simple Storage Service; http://aws.amazon.com/s3/). The VMs, however, are simply runtime entities. My personal and work data are held separately, mapped into the runtime upon boot, and independently backed up, block for block, onto S3. If I lose my laptop on any day, the hard disk is locked and the machine is of no use to anyone else. I purchase a new laptop, and within download time everything I have is back.
I also use Citrix WAN optimization technology to ensure that no block of data ever gets sent over the wire twice. A 24-MB PowerPoint file with just a few changes takes less than a second to back up because 99 percent of the blocks are already backed up and only the differences are sent over the wire. GUSTAV There’s a really powerful application that comes
with this. Along with day-to-day virtualization stuff, we have to consider the issue of DR (disaster recovery). Most SMBs make zero investment in DR. Virtualization becomes incredibly cost effective when it has the ability to send VMs to the cloud for access only when needed. CROSBY The benefits are huge, and the numbers are very compelling. GUSTAV Typical disaster-recovery costs are 2N (twice the cost of the infrastructure). To say that I can go to 1.05N is game changing. CROSBY The great thing about this kind of approach is that the cloud vendor can lose a data center, and my data is still there. They can lose two simultaneously, and my data is still there. CREEGER The virtualization abstraction enables fungible data-center capacity, much like the power industry, where people can trade excess capacity on the open market. CROSBY That’s right, and like the power industry, you will have purely financial players—people in the business who know nothing about technology, simply trading capacity back and forth. The first arbitrage players on the cloud are already in business. GUSTAV I will take it back to the insurance space. I can buy true insurance. I can pay 2 percent of the value of my assets today and know I can absolutely run my exact stuff. CREEGER So it’s a bulletproof insurance premium. BISHOP That’s right. It’s how you compute and manage risk. GUSTAV It’s “How do I take my 2N problem down to 0.02N?” It’s “How do I take 98 percent of my DR cost to zero?” That is just a different way of saying, “How do I take 49 percent of my total IT cost to zero?” CROSBY At the same time, the high-end FT (fault tolerance) moves down to a commoditized, value-priced capability rather than a high-end, hardware capability. GUSTAV To give you an example of the thinking behind DR, take 9/11. 9/11 was a black swan. Any statistical model that you build fails when the black swan shows up, and DR is valuable only if it actually works when the black swan shows up.
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