system performance tools for Linux

 The sysstat package contains the following system performance tools:
  - sar: collects and reports system activity information;
  - iostat: reports CPU utilization and disk I/O statistics;
  - tapestat: reports statistics for tapes connected to the system;
  - mpstat: reports global and per-processor statistics;
  - pidstat: reports statistics for Linux tasks (processes);
  - sadf: displays data collected by sar in various formats;
  - cifsiostat: reports I/O statistics for CIFS filesystems.
 .
 The statistics reported by sar deal with I/O transfer rates,
 paging activity, process-related activities, interrupts,
 network activity, memory and swap space utilization, CPU
 utilization, kernel activities and TTY statistics, among
 others. Both UP and SMP machines are fully supported.