# Periodically Print I/O Activity

This section describes how to monitor I/O activity on the system.

## iotop.stp

iotop prints out the top ten executables generating I/O traffic every 5-second interval, in descending order. Its output contains the process name and the amount of data read or written by the process, in KB. For example:

## iotop Sample Output

    [...]
             Process           KB Read      KB Written
                Xorg             50287               0
             staprun              3328               0
     multiload-apple              3039              23
                sshd               208               1
            floaters                14              62
      NetworkManager                15               0
     gnome-vfs-daemo                 8               0
               cupsd                 3               3
            sendmail                 4               0
       mixer_applet2                 3               0

             Process           KB Read      KB Written
                Xorg             51886               0
             staprun              3328               0
     multiload-apple              3039              23
                sshd              1344               4
               snmpd                90               0
            floaters                15              66
      NetworkManager                23               0
          irqbalance                16               0
     pam_timestamp_c                 9               0
            sendmail                 4               0

iotopoutput displays top I/O writes and reads within a random 10-second interval. Note that iotop also detects I/O resulting from SystemTap activity — iotopoutput displays reads done by `staprun`.