nfsv4fileio.d Reports Reads and Writes

This DTrace script prints a summary of file read and write bytes:

#!/usr/sbin/dtrace -s

#pragma D option quiet

dtrace:::BEGIN
{
        trace("Tracing... Hit Ctrl-C to end.\n");
}

nfsv4:::op-read-done
{
        @readbytes[args[1]->noi_curpath] = sum(args[2]->data_len);
}


nfsv4:::op-write-done
{
        @writebytes[args[1]->noi_curpath] = sum(args[2]->count);
}

dtrace:::END
{
        printf("\n%12s %12s  %s\n", "Rbytes", "Wbytes", "Pathname");
        printa("%@12d %@12d  %s\n", @readbytes, @writebytes);
}

This output shows a few files were read, and one was written:

# ./nfsv4fileio.d
Tracing... Hit Ctrl-C to end.
^C

      Rbytes       Wbytes  Pathname
           0       206663  /export/share/words1
       24528            0  /export/share/bin/xargs
       44864            0  /export/share/bin/ed
      232476            0  /export/share/bin/vi

The fields printed are:

Field	Description
Rbytes	Bytes read for this path name
Wbytes	Bytes written to this path name
Pathname	Path name of NFS file