Is it possible to set an arbitrary delay for I/O operations?
I would like to learn how do iowait and disk %util impact the performance. There are a lot of tools to stress the disk (bonnie++ etc.) but I'm looking for a way to introduce a delay like the tc (traffic control) tool does for network. It is possible to disable some optimizations with hdparm tool, like set AAM to quiet or disable DMA and switch to PIO mode - which are only a indirect way to decrease I/O.