James Litchfield wrote:
I've never seen the file name when doing this with ZFS.
My belief is that ZFS will cheerfully bundle a bunch of data
together from disparate files and spit it out to disk. It's done
with taskq threads so you can't tie the IO to a specific process.
For ZFS, this just doesn't work.
Jim
----
Thanks Jim.
Pramod Batni wrote:
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.
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.
Apologies. The previous statement is incorrect.
As Jim mentions, the file name does not show up when doing IO to files
on ZFS.
I just checked it out on a system and yes the script does not give the
name of the ZFS file which is
read/written to disk. The IO's are handled via zio's and there appears
to be no linkage from the zio to the vnode [where
the name is stored]
On a side note, the script does work for files residing on UFS.
Pramod
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