1.\" $NetBSD: iostat.8,v 1.22 2003/08/07 11:25:22 agc Exp $ 2.\" 3.\" Copyright (c) 1985, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)iostat.8 8.1 (Berkeley) 6/6/93 31.\" 32.Dd March 1, 2003 33.Dt IOSTAT 8 34.Os 35.Sh NAME 36.Nm iostat 37.Nd report 38.Tn I/O 39statistics 40.Sh SYNOPSIS 41.Nm 42.Op Fl CdDITx 43.Op Fl c Ar count 44.Op Fl M Ar core 45.Op Fl N Ar system 46.Op Fl w Ar wait 47.Op Ar drives 48.Sh DESCRIPTION 49.Nm 50displays kernel 51.Tn I/O 52statistics on terminal, disk and CPU operations. 53By default, 54.Nm 55displays one line of statistics averaged over the machine's run time. 56The use of 57.Fl c 58presents successive lines averaged over the 59.Ar wait 60period. 61The 62.Fl I 63option causes 64.Nm 65to print raw, unaveraged values. 66.Pp 67Only the last disk option specified 68.Fl ( d , 69.Fl D , 70or 71.Fl x ) 72is used. 73.Pp 74The options are as follows: 75.Bl -tag -width XNXsystemX 76.It Fl c Ar count 77Repeat the display 78.Ar count 79times. 80Unless the 81.Fl I 82flag is in effect, the first display is for the time since a reboot and 83each subsequent report is for the time period since the last display. 84If no 85.Ar wait 86interval is specified, the default is 1 second. 87.It Fl C 88Show CPU statistics. 89This is enabled by default unless the 90.Fl d , 91.Fl D , 92.Fl T , 93or 94.Fl x 95flags are used. 96.It Fl d 97Show disk statistics. 98This is the default. 99Displays kilobytes per 100transfer, number of transfers, and megabytes transferred. 101Use of this flag disables display of CPU and tty statistics. 102.It Fl D 103Show alternative disk statistics. 104Displays kilobytes transferred, number of 105transfers, and time spent in transfers. 106Use of this flag disables the default display. 107.It Fl I 108Show the running total values, rather than an average. 109.It Fl M Ar core 110Extract values associated with the name list from the specified core 111instead of the default 112.Dq Pa /dev/mem . 113.It Fl N Ar system 114Extract the name list from the specified system instead of the default 115.Dq Pa /netbsd . 116.It Fl T 117Show tty statistics. 118This is enabled by default unless the 119.Fl C , 120.Fl d , 121or 122.Fl D 123flags are used. 124.It Fl w Ar wait 125Pause 126.Ar wait 127seconds between each display. 128If no repeat 129.Ar count 130is specified, the default is infinity. 131.It Fl x 132Show extended disk statistics. 133Each disk is displayed on a line of its own with all available 134statistics. 135This option overrides all other display options, and all 136disks are displayed unless specific disks 137are provided as arguments. 138Additionally, separate read and write statistics are displayed. 139.El 140.Pp 141.Nm 142displays its information in the following format: 143.Bl -tag -width flag 144.It tty 145.Bl -tag -width indent -compact 146.It tin 147characters read from terminals 148.It tout 149characters written to terminals 150.El 151.It disks 152Disk operations. 153The header of the field is the disk name and unit number. 154If more than four disk drives are configured in the system, 155.Nm 156displays only the first four drives. 157To force 158.Nm 159to display specific drives, their names may be supplied on the command 160line. 161.Pp 162.Bl -tag -width indent -compact 163.It KB/t 164Kilobytes transferred per disk transfer 165.It t/s 166transfers per second 167.It MB/s 168Megabytes transferred per second 169.Pp 170.El 171The alternative display format, (selected with 172.Fl D ) , 173presents the following values. 174.Bl -tag -width indent -compact 175.It KB 176Kilobytes transferred 177.It xfr 178Disk transfers 179.It time 180Seconds spent in disk activity 181.El 182.It cpu 183.Bl -tag -width indent -compact 184.It \&us 185% of CPU time in user mode 186.It \&ni 187% of CPU time in user mode running niced processes 188.It \&sy 189% of CPU time in system mode 190.It \&id 191% of CPU time in idle mode 192.El 193.El 194.Sh FILES 195.Bl -tag -width /dev/mem -compact 196.It Pa /netbsd 197Default kernel namelist. 198.It Pa /dev/mem 199Default memory file. 200.El 201.Sh SEE ALSO 202.Xr fstat 1 , 203.Xr netstat 1 , 204.Xr nfsstat 1 , 205.Xr \&ps 1 , 206.Xr systat 1 , 207.Xr vmstat 1 , 208.Xr pstat 8 209.Pp 210The sections starting with ``Interpreting system activity'' in 211.%T "Installing and Operating 4.3BSD" . 212.Sh HISTORY 213.Nm 214appeared in 215.At v6 . 216The 217.Fl x 218option was added in 219.Nx 1.4 . 220