1 .TH iotop 1m "$Date:: 2007-08-05 #$" "USER COMMANDS"
3 iotop \- display top disk I/O events by process. Uses DTrace.
6 [\-C] [\-D|\-o|\-P] [\-j|\-Z] [\-d device] [\-f filename]
7 [\-m mount_point] [\-t top] [interval [count]]
9 iotop tracks disk I/O by process, and prints a summary report that
10 is refreshed every interval.
12 This is measuring disk events that have made it past system caches.
14 Since this uses DTrace, only the root user or users with the
15 dtrace_kernel privilege can run this command.
19 stable - needs the io provider.
23 don't clear the screen
26 print delta times - elapsed, us
32 print disk delta times, us
35 print %I/O (disk delta times)
41 instance name to snoop (eg, dad0)
44 full pathname of file to snoop
47 mountpoint for filesystem to snoop
54 Default output, print summary every 5 seconds
65 print %I/O (time based),
71 Snoop events on the root filesystem only,
76 Print top 20 lines only,
81 Print 12 x 5 second samples, scrolling,
104 command name for the process
116 direction, Read or Write
119 total size of operations, bytes
122 total elapsed times from request to completion, us (this is the elapsed
123 time from the disk request (strategy) to the disk completion (iodone))
126 total times for disk to complete request, us (this is the time for the
127 disk to complete that event since it's last event (time between iodones),
128 or, the time to the strategy if the disk had been idle)
131 percent disk I/O, based on time (DISKTIME)
134 1 minute load average
137 total disk read Kb for sample
140 total disk write Kb for sample
143 See the DTraceToolkit for further documentation under the
144 Docs directory. The DTraceToolkit docs may include full worked
145 examples with verbose descriptions explaining the output.
147 iotop will run forever until Ctrl\-C is hit, or the specified
153 iosnoop(1M), dtrace(1M)