I/O performance measurement and load generation tool Spew is used to measure I/O performance of character devices, block devices, and regular files. It can also be used to generate high I/O loads to stress systems while verifying data integrity. Spew is easy to use and is flexible. No configuration files or complicated client/server configurations are needed. Spew also generates its own data patterns that are designed to make it easy to find and debug data integrity problems.