fddist1m
File descriptor usage distributions. uses dtrace.
Usage
fddist [{-r | -w}]
Overview
This prints distributions for read and write events by file descriptor, by process. This can be used to determine which file descriptor a process is doing the most I/O with.
Since this uses DTrace, only users with root privileges can run this command.
Options
-
-r -
reads only
-
-w -
writes only
Examples
Sample both read and write activity,
|
# |
|---|---|
Sample reads only,
|
# |
Fields
EXEC
|
process name |
|---|---|
PID
|
process ID |
value
|
file descriptor |
count
|
number of events |
Based on
/usr/demo/dtrace/lquantize.d
Documentation
DTrace Guide "Aggregations" chapter (docs.sun.com)
See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with verbose descriptions explaining the output.
Exit
fddist will sample until Ctrl-C is hit.
Releases
115 releases since Mac OS X 10.5; the text changed 1 time.