iopattern - print disk I/O pattern. Uses DTrace.
iopattern [-v] [-d device] [-f filename] [-m mount_point] [interval [count]]
This prints details on the I/O access pattern for the disks, such as percentage of events that were of a random or sequential nature. By default totals for all disks are printed.
An event is considered random when the heads seek. This program prints the percentage of events that are random. The size of the seek is not measured - it's either random or not.
Since this uses DTrace, only users with root privileges can run this command.
See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with verbose descriptions explaining the output.
iopattern will run forever until Ctrl-C is hit, or the specified count is reached.
Brendan Gregg [Sydney, Australia]
iosnoop(1M), iotop(1M), dtrace(1M)
|July 25, 2005||version 0.70|