Monitoring and analyzing performance is an important task for any sysadmin. Disk I/O bottlenecks can bring applications to a crawl. What is an IOP? Should I use SATA, SAS, or FC? How many spindles do I need? What RAID level should I use? Is my system read or write heavy? These are common questions for anyone embarking on an disk I/O analysis quest. Obligatory disclaimer: I do not consider myself an expert in storage or anything for that mater. This is just how I have done I/O analysis in the past. I welcome additions and corrections. I believe itís also important to note that this analysis is geared toward random operations than sequential read/write workloads.
Read the full thing at http://www.cmdln.org/2010/04/22/analyzing-io-performance-in-linux/