.TH iotop 1m "Oct 25, 2005" "version 0.75" "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 users with root privileges can run this command. .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)