.TH iotop 1m  "$Date:: 2007-08-05 #$" "USER COMMANDS"
.SH NAME
iotop \- display top disk I/O events by process. Uses DTrace.
.SH SYNOPSIS
.B iotop
[\-C] [\-D|\-o|\-P] [\-j|\-Z] [\-d device] [\-f filename]
[\-m mount_point] [\-t top] [interval [count]]
.SH DESCRIPTION
iotop tracks disk I/O by process, and prints a summary report that
is refreshed every interval.

This is measuring disk events that have made it past system caches.

Since this uses DTrace, only the root user or users with the
dtrace_kernel privilege can run this command.
.SH OS
Solaris
.SH STABILITY
stable - needs the io provider.
.SH OPTIONS
.TP
\-C
don't clear the screen
.TP
\-D
print delta times - elapsed, us
.TP
\-j
print project ID
.TP
\-o
print disk delta times, us
.TP
\-P
print %I/O (disk delta times)
.TP
\-Z
print zone ID
.TP
\-d device
instance name to snoop (eg, dad0)
.TP
\-f filename
full pathname of file to snoop
.TP
\-m mount_point
mountpoint for filesystem to snoop
.TP
\-t top
print top number only
.PP
.SH EXAMPLES
.TP
Default output, print summary every 5 seconds
# 
.B iotop
.PP
.TP
One second samples,
# 
.B iotop
1
.PP
.TP
print %I/O (time based),
#
.B iotop
\-P
.PP
.TP
Snoop events on the root filesystem only,
#
.B iotop
\-m /
.TP
Print top 20 lines only,
#
.B iotop
\-t 20
.TP
Print 12 x 5 second samples, scrolling,
#
.B iotop
\-C 5 12
.PP
.SH FIELDS
.TP
UID
user ID
.TP
PID
process ID
.TP
PPID
parent process ID
.TP
PROJ
project ID
.TP
ZONE
zone ID
.TP
CMD
command name for the process
.TP
DEVICE
device name
.TP
MAJ
device major number
.TP
MIN
device minor number
.TP
D
direction, Read or Write
.TP
BYTES
total size of operations, bytes
.TP
ELAPSED
total elapsed times from request to completion, us (this is the elapsed 
time from the disk request (strategy) to the disk completion (iodone))
.TP
DISKTIME
total times for disk to complete request, us (this is the time for the 
disk to complete that event since it's last event (time between iodones),
or, the time to the strategy if the disk had been idle)
.TP
%I/O
percent disk I/O, based on time (DISKTIME)
.TP
load
1 minute load average
.TP
disk_r
total disk read Kb for sample
.TP
disk_w
total disk write Kb for sample
.PP
.SH DOCUMENTATION
See the DTraceToolkit for further documentation under the 
Docs directory. The DTraceToolkit docs may include full worked
examples with verbose descriptions explaining the output.
.SH EXIT
iotop will run forever until Ctrl\-C is hit, or the specified
interval is reached.
.SH AUTHOR
Brendan Gregg
[Sydney, Australia]
.SH SEE ALSO
iosnoop(1M), dtrace(1M)