iostat

iostat(1)						      General Commands Manual							 iostat(1)

Name
       iostat - report I/O statistics

Syntax
       iostat [ -c ] [ -t ] [ disknames ] [ interval ] [ count ]

Description
       The  command  reports  I/O  statistics for terminals, disks and cpus.  For terminals the number of input and output characters are counted.
       For disks the number of 512 byte blocks per second and number of transfers per second are displayed.  For cpus, it provides the	percentage
       of  time  the system has spent in user mode, in user mode running low priority (niced) processes, in system mode, and idling.  On multipro-
       cessor systems these cpu statistics represent a cumulative summary of all the cpus.

       The optional disknames argument causes disk statistics to be displayed for the specified disks.	If this argument  is  not  specified  then
       disk statistics will be displayed for the first 3 disks only.

       The  optional interval argument causes to report once each interval seconds.  The first report is for all time since a reboot and each sub-
       sequent report is for the last interval only.

       The optional count argument restricts the number of reports.

Options
       -c   Displays the percentage of time each cpu spent in user mode, running low priority (nice'd) processes, in system mode, and idling.

       -t   Displays the number of characters read from and written to terminals.

Examples
       This example will cause cpu and disk statistics for the 5 disks ra0, ra1, ra2, ra3, and ra4.
	    iostat ra0 ra1 ra2 ra3 ra4
       This example will cause cpu, terminal, and disk statistics for ra0 to be displayed and updated every 2 seconds.
	    iostat -t ra0 2

Files
See Also
       vmstat(1), cpustat(1)

																	 iostat(1)