The MONITOR DISK command initiates monitoring of the DISK
    statistics class. The maximum number of disks that can be
    monitored for record output is 909, and for display and summary
    output is 1817.

    Format

      MONITOR DISK

1  –  Classname Qualifiers

1.1    /ALL

    Specifies that a table of all available statistics (current,
    average, minimum, and maximum) is to be included in the display
    and summary output. For summary output, this qualifier is the
    default for all classes; otherwise, it is the default for all
    classes except CLUSTER, MODES, PROCESSES, STATES, SYSTEM, and
    VECTOR.

1.2    /AVERAGE

    Specifies that a bar graph of average statistics is to be
    included in the display and summary outputs.

1.3    /CURRENT

    Specifies that a bar graph of current statistics is to be
    included in the display and summary outputs. The /CURRENT
    qualifier is the default for the CLUSTER, MODES, STATES, SYSTEM,
    and VECTOR classes.

1.4    /ITEM

       /ITEM=(keyword[,...])

    Selects one or more data items for inclusion in display and
    summary outputs. If you specify two or more keywords, enclose
    them in parentheses, and separate them with commas. When the
    /ITEM qualifier is omitted, the default is /ITEM=OPERATION_RATE.

    The following table describes /ITEM qualifier keywords:

    Keyword       Description

    ALL           Specifies that statistics on all data items
                  collected for the disks are displayed on successive
                  screens.
    OPERATION_    Specifies that I/O operation rate statistics are
    RATE          displayed for each disk.
    QUEUE_LENGTH  Specifies that the number of I/O request packets
                  being serviced (current or waiting) is displayed
                  for each disk.

1.5    /MAXIMUM

    Specifies that a bar graph of maximum statistics is to be
    included in the display and summary outputs.

1.6    /MINIMUM

    Specifies that a bar graph of minimum statistics is to be
    included in the display and summary outputs.

1.7    /PERCENT

       /PERCENT
       /NOPERCENT (default)

    Controls whether statistics are expressed as percent values in
    display and summary outputs. The /PERCENT qualifier is applicable
    only to the DISK, MODES, SCS, and STATES classes.