rwbytype_example.txt   [plain text]

The following is an example fo the rwbytype.d script.


We run rwbytype.d for a few seconds then hit Ctrl-C,

   # rwbytype.d
   Tracing... Hit Ctrl-C to end.
   ^C
   PID    CMD               VTYPE  DIR     BYTES
   1545   sshd                chr    W         1
   10357  more                chr    R        30
   2357   sshd                chr    W        31
   10354  dtrace              chr    W        32
   1545   sshd                chr    R        34
   6778   bash                chr    W        44
   1545   sshd               sock    R        52
   405    poold               reg    W        68
   1545   sshd               sock    W       136
   10357  bash                reg    R       481
   10356  find                reg    R       481
   10355  bash                reg    R       481
   10357  more                reg    R      1652
   2357   sshd               sock    R      1664
   10357  more                chr    W     96925
   10357  more               fifo    R     97280
   2357   sshd                chr    R     98686
   10356  grep               fifo    W    117760
   2357   sshd               sock    W    118972
   10356  grep                reg    R    147645

Here we can see that the grep process with PID 10356 read 147645 bytes
from "regular" files. These are I/O bytes at the application level, so
much of these read bytes would have been cached by the filesystem page cache.

vnode file types are listed in /usr/include/sys/vnode.h, and give an idea of
what the file descriptor refers to.