[ Originally published at http://blogs.sun.com/bobs on Friday Feb 09, 2007 ]
For your reading pleasure, today I’m publicly posting a paper I wrote back in 2001 called “Oracle I/O: Supply and Demand“. This paper was delivered at our Sun User’s Performance Group (SUPerG) conference in Amsterdam in October of that year, but never made widely available to non-attendees. Though the paper is a little dated, it still represents my approach to explaining I/O in general. That is, what you measure with Oracle, iostat, or any other tool – will be the result of some demand factors constrained by some supply factors. Sounds simple, eh? I’ve found that illuminating both supply and demand factors – and showing how they interact – is the key to untangling the physics of any given situation. While the principle is simple, “the devil is in the details“, and those details are continuously in flux!
If I ever write a book, this will be the basis for a chapter in it! I hope that making this paper available here will help others further their holistic understanding of disk I/O in general! This paper could be enhanced by discussion of other factors, including NFS, ASM, and RAC/grid factors for example – but I’m more likely to blog about such things than take a stab at a Grand Unified White Paper in the near future.
I’ll never forget that trip to Amsterdam! It was just after 9/11. Air travel was rather tense, to say the least. SUPerG attendance from some parts of the world was severely impacted. Sadly, in the time since, Sun’s SUPerG program has wound down. I have many fond memories from my SUPerG outings!
