iopending - plot number of pending disk events. Uses DTrace.
iopending [-c] [-d device] [-f filename] [-m mount_point] [interval [count]]
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.
Dr Rex di Bona
See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with verbose descriptions explaining the output.
iopending will run forever until Ctrl-C is hit, or the specified count is reached.
Brendan Gregg [Sydney, Australia]
iosnoop(1M), iotop(1M), dtrace(1M)
|November 1, 2005||version 0.60|