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Annotation of cci/usr/src/man/man1/iostat.1, revision 1.1.1.2

1.1       root        1: .TH IOSTAT 1 "18 January 1983"
                      2: .UC 4
                      3: .SH NAME
                      4: iostat \- report I/O statistics
                      5: .SH SYNOPSIS
                      6: .B iostat
1.1.1.2 ! root        7: [ [-01r] interval [ count ] ]
1.1       root        8: .SH DESCRIPTION
                      9: .I Iostat
1.1.1.2 ! root       10: iteratively reports the number of 
        !            11: characters read and written to terminals,
        !            12: and, for each disk, the number of 
        !            13: seeks per second, transfers per second, 
        !            14: kilobytes transferred per second,
        !            15: and the milliseconds per average 
        !            16: transfer which include the seek time.
1.1       root       17: It also gives the percentage of time the system has
1.1.1.2 ! root       18: spent in user mode, in user mode running 
        !            19: low priority (niced) processes,
1.1       root       20: in system mode, and idling.
                     21: .PP
1.1.1.2 ! root       22: To compute this information, 
        !            23: for each disk, seeks and data transfer completions
1.1       root       24: and number of words transferred are counted;
                     25: for terminals collectively, the number
                     26: of input and output characters are counted.
                     27: Also, each sixtieth of a second,
                     28: the state of each disk is examined
                     29: and a tally is made if the disk is active.
1.1.1.2 ! root       30: From these numbers, and given the transfer rates
        !            31: of the devices, it is possible to determine
1.1       root       32: average seek times for each device.
                     33: .PP
1.1.1.2 ! root       34: The POWER 6/32 can support up to 32 disk drives.  
        !            35: .I Iostat 
        !            36: can only display 16 drives at one time.
        !            37: The 
        !            38: .B \-0
        !            39: argument will display the first 16 mounted disk drives, 
        !            40: and the
        !            41: .B \-1
        !            42: argument will display the second 16 mounted disk drives. 
        !            43: These options take effect only if the system has more
        !            44: than 16 mounted drives.
        !            45: The
        !            46: .B \-0
        !            47: argument is the default.  
        !            48: Any time during the display, you can type in
        !            49: a 0, 1 or r to change the display.
        !            50: .PP
        !            51: The
        !            52: .B \-r
        !            53: argument, switches between displaying the 
        !            54: first and second 16 disk drives, i.e., it switches 
        !            55: back and forth between the 0 and 1 options.
        !            56: This option takes effect only if the system has more
        !            57: than 16 mounted drives.
        !            58: The duration for each set of drives will be [interval]/2 .
        !            59: .PP
1.1       root       60: The optional
                     61: .I interval
                     62: argument causes
                     63: .I iostat
                     64: to report once each
                     65: .I interval
                     66: seconds.
                     67: The first report is for  all time since a reboot and each
                     68: subsequent report is for the last interval only.
                     69: .PP
                     70: The optional
                     71: .I count
                     72: argument restricts the number of reports.
                     73: .SH FILES
                     74: /dev/kmem
                     75: .br
                     76: /vmunix
                     77: .SH SEE ALSO
                     78: vmstat(1)

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