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iopending(1m) [osx man page]

iopending(1m)							   USER COMMANDS						     iopending(1m)

NAME
iopending - plot number of pending disk events. Uses DTrace. SYNOPSIS
iopending [-c] [-d device] [-f filename] [-m mount_point] [interval [count]] DESCRIPTION
This samples the number of disk events that are pending and plots a distribution graph. By doing this the "serialness" or "parallelness" of disk behaviour can be distinguished. A high occurance of a pending value of more than 1 is an indication of saturation. Since this uses DTrace, only users with root privileges can run this command. OPTIONS
-c clear screen -d device instance name to snoop (eg, dad0) -f filename full pathname of file to snoop -m mount_point mountpoint for filesystem to snoop EXAMPLES
Default output, print I/O summary every 1 second, # iopending Print 10 second samples, # iopending 10 Print 12 x 5 second samples, # iopending 5 12 Snoop events on the root filesystem only, # iopending -m / FIELDS
value number of pending events, 0 == idle count number of samples @ 1000 Hz load 1 min load average disk_r total disk read Kb for sample disk_w total disk write Kb for sample IDEA
Dr Rex di Bona DOCUMENTATION
See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with ver- bose descriptions explaining the output. EXIT
iopending will run forever until Ctrl-C is hit, or the specified count is reached. AUTHOR
Brendan Gregg [Sydney, Australia] SEE ALSO
iosnoop(1M), iotop(1M), dtrace(1M) version 0.60 Nov 01, 2005 iopending(1m)

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iotop(1m)							   USER COMMANDS							 iotop(1m)

NAME
iotop - display top disk I/O events by process. Uses DTrace. SYNOPSIS
iotop [-C] [-D|-o|-P] [-j|-Z] [-d device] [-f filename] [-m mount_point] [-t top] [interval [count]] 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 users with root privileges can run this command. OPTIONS
-C don't clear the screen -D print delta times - elapsed, us -j print project ID -o print disk delta times, us -P print %I/O (disk delta times) -Z print zone ID -d device instance name to snoop (eg, dad0) -f filename full pathname of file to snoop -m mount_point mountpoint for filesystem to snoop -t top print top number only EXAMPLES
Default output, print summary every 5 seconds # iotop One second samples, # iotop 1 print %I/O (time based), # iotop -P Snoop events on the root filesystem only, # iotop -m / Print top 20 lines only, # iotop -t 20 Print 12 x 5 second samples, scrolling, # iotop -C 5 12 FIELDS
UID user ID PID process ID PPID parent process ID PROJ project ID ZONE zone ID CMD command name for the process DEVICE device name MAJ device major number MIN device minor number D direction, Read or Write BYTES total size of operations, bytes ELAPSED total elapsed times from request to completion, us (this is the elapsed time from the disk request (strategy) to the disk completion (iodone)) 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) %I/O percent disk I/O, based on time (DISKTIME) load 1 minute load average disk_r total disk read Kb for sample disk_w total disk write Kb for sample DOCUMENTATION
See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with ver- bose descriptions explaining the output. EXIT
iotop will run forever until Ctrl-C is hit, or the specified interval is reached. AUTHOR
Brendan Gregg [Sydney, Australia] SEE ALSO
iosnoop(1M), dtrace(1M) version 0.75 Oct 25, 2005 iotop(1m)
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