Monitor performance of various Linux subsystems.

# To report I/O and transfer rate issued to physical devices, one per second (press CTRL+C to quit):
sar -b 1

# To report a total of 10 network device statistics, one per 2 seconds:
sar -n DEV 2 10

# To report CPU utilization, one per 2 seconds:
sar -u ALL 2

# To report a total of 20 memory utilization statistics, one per second:
sar -r ALL 1 20

# To report the run queue length and load averages, one per second:
sar -q 1

# To report paging statistics, one per 5 seconds:
sar -B 5