Slower performance after enabling async io on Oracle Linux

From: Matthias Hoys <>
Date: Mon, 14 May 2012 02:03:56 -0700 (PDT)
Message-ID: <27769382.324.1336986236654.JavaMail.geo-discussion-forums_at_vbyg17>


Platform is Oracle Linux 6.2 64-bit with Oracle 64-bit.

After enabling async io, I see slower performance for data pump exports, RMAN backups and long-running queries (between 10 and 15% slower).

I enabled async io with:

ALTER SYSTEM SET FILESYSTEMIO_OPTIONS=SETALL SCOPE=SPFILE; aio-nr is 19052 and aio-max-nr is 1048576. Storage is on iSCSI.

Anyone else with the same experience? Is extra tuning for async io possible on Oracle Linux?

Matthias Hoys Received on Mon May 14 2012 - 04:03:56 CDT

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