[unix-history] / usr / src / usr.sbin / iostat / iostat.8

.\" Copyright (c) 1985, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" %sccs.include.redist.roff%
.\"
.\"	@(#)iostat.8	8.1 (Berkeley) %G%
.\"
.Dd 
.Dt IOSTAT 8
.Os BSD 4
.Sh NAME
.Nm iostat
.Nd report
.Tn I/O
statistics
.Sh SYNOPSIS
.Nm iostat
.Op Fl c Ar count
.Op Fl M Ar core
.Op Fl N Ar system
.Op Fl w Ar wait
.Op Ar drives
.Sh DESCRIPTION
.Nm Iostat
displays kernel
.Tn I/O
statistics on terminal, disk and cpu
operations.
.Pp
The options are as follows:
.Bl -tag -width flag
.It Fl c
Repeat the display
.Ar count
times.
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
.Ar wait
interval is specified, the default is 1 second.
.It Fl M
Extract values associated with the name list from the specified core
instead of the default
.Dq Pa /dev/kmem .
.It Fl N
Extract the name list from the specified system instead of the default
.Dq Pa /vmunix .
.It Fl w
Pause
.Ar wait
seconds between each display.
If no repeat
.Ar count
is specified, the default is infinity.
.El
.Pp
.Nm Iostat
displays its information in the following format:
.Bl -tag -width flag
.It tty
.Bl -tag -width indent -compact
.It tin
characters read from terminals
.It tout
characters written to terminals
.El
.It disks
Disk operations (this field is system dependent). 
The header of the field is the disk name and unit number.
If more than four disk drives are configured in the system,
.Nm iostat
displays only the first four drives.
To force
.Nm iostat
to display specific drives, their names may be supplied on the command
line.
.Pp
.Bl -tag -width indent -compact
.It sps
sectors transferred per second
.It tps
transfers per second
.It msps
milliseconds per average seek (including implied
seeks and rotational latency)
.El
.It cpu
.Bl -tag -width indent -compact
.It \&us
% of cpu time in user mode
.It \&ni
% of cpu time in user mode running niced processes
.It \&sy
% of cpu time in system mode
.It \&id
% of cpu time in idle mode
.El
.El
.Sh FILES
.Bl -tag -width /dev/kmem -compact
.It Pa /vmunix
Default kernel namelist.
.It Pa /dev/kmem
Default memory file.
.El
.Sh SEE ALSO
.Xr fstat 1 ,
.Xr netstat 1 ,
.Xr nfsstat 1 ,
.Xr \&ps 1 ,
.Xr systat 1 ,
.Xr vmstat 1 ,
.Xr pstat 8
.Pp
The sections starting with ``Interpreting system activity'' in
.%T "Installing and Operating 4.3BSD" .
Commit	Line	Data
ba0afae5 KB	1	.\" Copyright (c) 1985, 1991, 1993
ba0afae5 KB	2	.\" The Regents of the University of California. All rights reserved.
3a672b8e	3	.\"
aa4fee89	4	.\" %sccs.include.redist.roff%
cf1d1622	5	.\"
ba0afae5	6	.\" @(#)iostat.8 8.1 (Berkeley) %G%
3a672b8e	7	.\"
a5b51844 CL	8	.Dd
	9	.Dt IOSTAT 8
	10	.Os BSD 4
	11	.Sh NAME
	12	.Nm iostat
	13	.Nd report
	14	.Tn I/O
	15	statistics
	16	.Sh SYNOPSIS
	17	.Nm iostat
	18	.Op Fl c Ar count
	19	.Op Fl M Ar core
	20	.Op Fl N Ar system
	21	.Op Fl w Ar wait
	22	.Op Ar drives
	23	.Sh DESCRIPTION
	24	.Nm Iostat
	25	displays kernel
	26	.Tn I/O
	27	statistics on terminal, disk and cpu
	28	operations.
	29	.Pp
a6057ab7	30	The options are as follows:
a5b51844 CL	31	.Bl -tag -width flag
a5b51844 CL	32	.It Fl c
42e4bb6a	33	Repeat the display
a5b51844	34	.Ar count
a6057ab7	35	times.
9835199b KB	36	The first display is for the time since a reboot and each subsequent
9835199b KB	37	report is for the time period since the last display.
f2f79253	38	If no
a5b51844	39	.Ar wait
f2f79253	40	interval is specified, the default is 1 second.
a5b51844	41	.It Fl M
42e4bb6a	42	Extract values associated with the name list from the specified core
a5b51844 CL	43	instead of the default
	44	.Dq Pa /dev/kmem .
	45	.It Fl N
42e4bb6a	46	Extract the name list from the specified system instead of the default
a5b51844 CL	47	.Dq Pa /vmunix .
a5b51844 CL	48	.It Fl w
42e4bb6a	49	Pause
a5b51844	50	.Ar wait
42e4bb6a	51	seconds between each display.
f2f79253	52	If no repeat
a5b51844	53	.Ar count
f2f79253	54	is specified, the default is infinity.
a5b51844 CL	55	.El
	56	.Pp
	57	.Nm Iostat
9835199b	58	displays its information in the following format:
a5b51844 CL	59	.Bl -tag -width flag
	60	.It tty
	61	.Bl -tag -width indent -compact
	62	.It tin
	63	characters read from terminals
	64	.It tout
	65	characters written to terminals
	66	.El
	67	.It disks
9835199b KB	68	Disk operations (this field is system dependent).
	69	The header of the field is the disk name and unit number.
	70	If more than four disk drives are configured in the system,
a5b51844	71	.Nm iostat
9835199b	72	displays only the first four drives.
a6057ab7	73	To force
a5b51844	74	.Nm iostat
a6057ab7 KB	75	to display specific drives, their names may be supplied on the command
a6057ab7 KB	76	line.
a5b51844 CL	77	.Pp
	78	.Bl -tag -width indent -compact
	79	.It sps
	80	sectors transferred per second
	81	.It tps
	82	transfers per second
	83	.It msps
	84	milliseconds per average seek (including implied
	85	seeks and rotational latency)
	86	.El
	87	.It cpu
	88	.Bl -tag -width indent -compact
	89	.It \&us
	90	% of cpu time in user mode
	91	.It \&ni
	92	% of cpu time in user mode running niced processes
	93	.It \&sy
	94	% of cpu time in system mode
	95	.It \&id
	96	% of cpu time in idle mode
	97	.El
	98	.El
	99	.Sh FILES
	100	.Bl -tag -width /dev/kmem -compact
	101	.It Pa /vmunix
	102	Default kernel namelist.
	103	.It Pa /dev/kmem
	104	Default memory file.
	105	.El
	106	.Sh SEE ALSO
	107	.Xr fstat 1 ,
	108	.Xr netstat 1 ,
	109	.Xr nfsstat 1 ,
	110	.Xr \&ps 1 ,
	111	.Xr systat 1 ,
	112	.Xr vmstat 1 ,
	113	.Xr pstat 8
	114	.Pp
42e4bb6a	115	The sections starting with ``Interpreting system activity'' in
a5b51844	116	.%T "Installing and Operating 4.3BSD" .