On Wed, 16 Jul 2003, Rob van der Heij wrote: > G. Johnny Dome wrote: > > > Actually a very good dasd benchmark tool to use is iozone, if anyone is > > interested > > No doubt iozone does very extensive tests to show different type of cache > and blocking. Often it is hard to tell what these results to do real life > applications. Especially with something as complex as disk I/O. > Also, when the benchmark does the measurements on Linux and Linux is not > able to keep track of time (because it runs on z/VM) the values are not > very useful (I have bonnie reports tell me it used 220% of one CPU). > The Redbook referenced in the thread (which I recommend strongly ;-) > compares Linux numbers with VM numbers to validate the results. > > Another thing to keep in mind is that imho with Linux on z/VM you care > about total progress made on the system, not necessarily the maximum > throughput achieved in a single virtual machine. The is measuring the > mileage of your car versus top speed. Most likely you don't achieve the > best mileage operating at top speed.
Or the speed of a car with the capacity of a bus. -- Cheers John. Join the "Linux Support by Small Businesses" list at http://mail.computerdatasafe.com.au/mailman/listinfo/lssb Copyright John Summerfield. Reproduction prohibited.
