List out a few performance monitoring tools.

Vmstat

This command is used to know virtual memory statistics

$ vmstat n

n – Interval in seconds

$ vmstat –s {to know the system events since the last boot}

$ vmstat –S {to show the swapping statistics}

$ vmstat –i {to show the interrupts per device}

Iostat

This command is used to display the statistics about disk input and output.

$ iostat 5

$ iostat –xtc { to show extended disk statistics}

df

This command is used to know the free space on the mounted disk.

$df –k {to show the disk space in kilobytes}