I am pretty sure many of you know the system monitoring tool "nmon", monitoring CPU, storage (disk), network, ... performance and utilization.
From the same source comes a workload generation tool-set "nstess". One component of it is the storage IO workload generator tool ndisk.
Now this tool is available for LINUX as well. Of course this tool is "As is" software, without any warranty.
compiled with gcc on SLES11 (runs on RedHat as well) ndisk for LINUX x84-64