RE: Solaris Direct I/O

From: Josh Collier <>
Date: Tue, 9 Feb 2010 09:30:38 -0800
Message-ID: <C5671700C5F4EA47B08AB9E6DAE9539B383BF56DE3_at_M1EXCHANGE01.mmi.local>

I can answer 2 of these, at least this is understand:
  1. Check the mount options with your sysadmin, they should look like this ,mincache=direct,convosync=direct, this will set things up for direct i/o.
  2. Use truss, if you see kaio failure followed by several lwp processes spawning then you are using async i/o. solaris implements kernalized async i/o, so the kaio calls will fail and the OS will respond with several LWP serial process to simulate async i/o. with filesystem options to SETALL, it should be doing async i/o.

From: [] On Behalf Of Taral Desai Sent: Monday, February 08, 2010 10:45 PM To:
Subject: Solaris Direct I/O

Hi All,

We are using sparc 64bit v 10 with oracle Above that we use SAN storage.

  1. How to find if storage is mounted for direct or async io
  2. We had set filesystem option to setall. How to verify it's doing direct or async. As with truss i see many kaio failure and then it invokes lwp process which do i/o in chunks. So, is there a different call for SAN.

3 Is there any benefit using veritas ODM over oracle ODM ?

Received on Tue Feb 09 2010 - 11:30:38 CST

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