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 users with root privileges 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 ver-
       bose 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)