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bitesize.d(1m)                                  USER COMMANDS                                 bitesize.d(1m)



NAME
       bitesize.d - analyse disk I/O size by process. Uses DTrace.

SYNOPSIS
       bitesize.d

DESCRIPTION
       This  produces  a  report  for the size of disk events caused by processes. These are the disk events
       sent by the block I/O driver.

       If applications must use the disks, we generally prefer they do so sequentially with large I/O sizes,
       or larger "bites".

       Since  this  uses  DTrace,  only the root user or users with the dtrace_kernel privilege can run this
       command.

EXAMPLES
       Sample until Ctrl-C is hit then print report,
              # bitesize.d


FIELDS
       PID    process ID

       CMD    command and argument list

       value  size in bytes

       count  number of I/O operations


NOTES
       The application may be requesting smaller sized operations, which are being rounded up to the nearest
       sector size or UFS block size.

       To analyse what the application is requesting, DTraceToolkit programs such as Proc/fddist may help.


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.

EXIT
       bitesize.d will sample until Ctrl-C is hit.

AUTHOR
       Brendan Gregg [Sydney, Australia]

SEE ALSO
       iosnoop(1M), seeksize(1M), dtrace(1M)




version 1.00                                    Jun 15, 2005                                  bitesize.d(1m)