1.\" Copyright (c) 1985, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)iostat.8 8.1 (Berkeley) 6/6/93 33.\" $Id: iostat.8,v 1.6 1994/05/14 21:52:21 cgd Exp $ 34.\" 35.Dd June 6, 1993 36.Dt IOSTAT 8 37.Os BSD 4 38.Sh NAME 39.Nm iostat 40.Nd report 41.Tn I/O 42statistics 43.Sh SYNOPSIS 44.Nm iostat 45.Op Fl c Ar count 46.Op Fl M Ar core 47.Op Fl N Ar system 48.Op Fl w Ar wait 49.Op Ar drives 50.Sh DESCRIPTION 51.Nm Iostat 52displays kernel 53.Tn I/O 54statistics on terminal, disk and cpu 55operations. 56.Pp 57The options are as follows: 58.Bl -tag -width flag 59.It Fl c 60Repeat the display 61.Ar count 62times. 63The first display is for the time since a reboot and each subsequent 64report is for the time period since the last display. 65If no 66.Ar wait 67interval is specified, the default is 1 second. 68.It Fl M 69Extract values associated with the name list from the specified core 70instead of the default 71.Dq Pa /dev/kmem . 72.It Fl N 73Extract the name list from the specified system instead of the default 74.Dq Pa /netbsd . 75.It Fl w 76Pause 77.Ar wait 78seconds between each display. 79If no repeat 80.Ar count 81is specified, the default is infinity. 82.El 83.Pp 84.Nm Iostat 85displays its information in the following format: 86.Bl -tag -width flag 87.It tty 88.Bl -tag -width indent -compact 89.It tin 90characters read from terminals 91.It tout 92characters written to terminals 93.El 94.It disks 95Disk operations (this field is system dependent). 96The header of the field is the disk name and unit number. 97If more than four disk drives are configured in the system, 98.Nm iostat 99displays only the first four drives. 100To force 101.Nm iostat 102to display specific drives, their names may be supplied on the command 103line. 104.Pp 105.Bl -tag -width indent -compact 106.It sps 107sectors transferred per second 108.It tps 109transfers per second 110.It msps 111milliseconds per average seek (including implied 112seeks and rotational latency) 113.El 114.It cpu 115.Bl -tag -width indent -compact 116.It \&us 117% of cpu time in user mode 118.It \&ni 119% of cpu time in user mode running niced processes 120.It \&sy 121% of cpu time in system mode 122.It \&id 123% of cpu time in idle mode 124.El 125.El 126.Sh FILES 127.Bl -tag -width /dev/kmem -compact 128.It Pa /netbsd 129Default kernel namelist. 130.It Pa /dev/kmem 131Default memory file. 132.El 133.Sh SEE ALSO 134.Xr fstat 1 , 135.Xr netstat 1 , 136.Xr nfsstat 1 , 137.Xr \&ps 1 , 138.Xr systat 1 , 139.Xr vmstat 1 , 140.Xr pstat 8 141.Pp 142The sections starting with ``Interpreting system activity'' in 143.%T "Installing and Operating 4.3BSD" . 144