Tools

Monitoring Can be built into a system Trace activity with timestamps Often uses the logging system COST 10% of resources

System tools SAR PS Profiling Accounting data

SAR Samples activity counters in the OS Sample rate is selectable Params: File access routines Buffer usage Cache hits System calls I/O activity Virtual memory CPU utilization

PS Report activity of processes: Status Priority Process Hierarchy Memory size Execution time

Profiling Compiled into executables Gives execution time for the routines in the code

Accounting Data Some OS have accounting data Gives usage params

prototyping Use the prototype to get initial performance data