[dtrace-discuss] File name not being displayed.

Pramod Batni
2009-08-16T20:50:34Z

vhiz wrote:
> Hi Pramod,
>
>                      I am using the ZFS filesystem on OpenSolaris. The
thing is that the file that my program is reading is 2.5 GB in size, which is
greater than the RAM size. Will caching still take place? And when I run the
script, I can see that the number of reads that it displays goes up quite a bit.
So the reads are being captured, just that the file name is not being displayed.
>
>
So you see <unknown> instead of the name of the file ?

Notice that your script is using fi_pathname to print the pathname of
the file which is undergoing IO.
>From  ''http://wikis.sun.com/display/DTrace/io+Provider''
--snip--
The fi_name field contains the name of the file but does not include any
directory components. If no file information is associated with an I/O,
the fi_name field will be set to the string <none>. In some rare cases,
the pathname associated with a file might be unknown. In this case, the
fi_name field will be set to the string <unknown>.
The fi_pathname field contains the full pathname to the file. As with
fi_name, this string may be set to <none> if no file information is
present, or <unknown> if the pathname associated with the file is not
known.
--snip--
I suspect {need to verify} that reading in the large file [more than the
RAM size] is blowing out the v_path information from the vnode.

Pramod

> Thanks.
>