| IOSTAT(8) | System Manager's Manual | IOSTAT(8) | 
iostat —
| iostat | [ -CdDITxyz] [-ccount] [-Hheight] [-Wwidth] [-wwait] [drives] | 
iostat displays kernel I/O statistics on terminal, disk
  and CPU operations. By default, iostat displays one
  line of statistics averaged over the machine's run time. The use of
  -c or -w presents successive
  lines averaged over the wait period. The
  -I option causes iostat to
  print raw, unaveraged values (totals).
Only the last disk option specified (-d,
    -D, -x, or
    -y) is used.
The options are as follows:
-c
    count-I flag is in effect, the first display is for the
      time since a reboot and each subsequent report is for the time period
      since the last display. If no wait interval is
      specified, the default is 1 second.-C-d, -D,
      -T, -x, or
      -y flags are used.-d-D-I). Use of this flag disables the default
      display.-H
    heightLINES if set, or from the
      terminal (window) size, if output is to a terminal and its size is set,
      and otherwise defaults to 20. If explicitly set to zero, pages are
      considered to be infinitely long. This parameter determines the frequency
      at which repeated headers are output. If the value is greater than zero,
      but too small for the header, along with one output set, then a new header
      will be produced for each set of output.-I-T-C, -d,
      -D, -x, or
      -y flags are used.-w
    wait-W
    widthCOLUMNS if set, or from the
      terminal (window) size, if output is to a terminal and its size is set,
      and otherwise defaults to 80. If explicitly set to 0, lines are considered
      infinitely long. This width is used only to determine the number of drives
      to display by default when no drive list is given. In other cases output
      will be as wide as needed to display the data requested.-x-C and
      -T options are ignored with this output
    format.-y-x) and
      additional queuing statistics. Output does not fit in an 80 column window.
      The -C and -T options are
      ignored with this output format.-z-I, has never done
      any I/O.iostat displays its information in the
    following format:
iostat displays only those drives that
      fit on the display. To force iostat to display
      specific drives, they may be supplied on the command line, either as names
      or fnmatch() patterns.
    
    The alternative display format, (selected with
        -D), presents the following values:
With the -y flag, the following
        queuing measurements are added:
Note that because of rounding, these percentages may appear to total more or less than 100.
The sections starting with ``Interpreting system activity'' in Installing and Operating 4.3BSD.
iostat appeared in Version 6
  AT&T UNIX. The -x option was added in
  NetBSD 1.4. Collection of queuing values and the
  -y option were added in NetBSD
  8.0. The archaic option format:
iostat [drives ...]
  [wait [count]]
| June 18, 2022 | NetBSD 10.1 |