RE: direct reads and writes on Solaris

Visit following URLs

 

http://www.solarisinternals.com/wiki/index.php/Direct_I/O

 

http://www.ixora.com.au/notes/filesystemio_options.htm

 

 

 

From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Dan Norris
Sent: Friday, January 25, 2008 7:14 AM
To: Oracle L
Subject: direct reads and writes on Solaris

 

Can someone help me interpret this set of data correctly? 

The (vxfs) filesystem is mounted with these options:
/db51 on /dev/vx/dsk/oracledg/db18
read/write/setuid/mincache=direct/delaylog/largefiles/ioerror=mwdisable/dev=
3ac36c1

This is 9.2.0.8 on Solaris 9 (V490, Generic_122300-07) with VxFS 4.1.

I have the following line in a truss of a dedicated server process:

open("/db51/oradata/tccrt1/member_questions_d01.dbf", O_RDWR|O_DSYNC) = 9

I also have the following settings in the DB:

NAME                                 TYPE        VALUE
------------------------------------ ----------- ---------------------------
---
disk_asynch_io                       boolean     TRUE
filesystemio_options                 string      ASYNCH

The question(s):
I was expecting to see O_DIRECT in there somehow, but I'm thinking that
maybe that's just on Linux, not Solaris. I don't see O_DIRECT listed in the
open(2) manual page. I am also wondering if filesystemio_options needs to
be "setall" instead of the current setting of "ASYNCH" in order to achieve
directIO. Or, am I looking at the wrong thing to determine if directIO is
enabled?

Thanks in advance!

Dan

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