filesystemio_options setting

Hi. We are running oracle 10.2.0.3 on our test evironment in suse 9. Emc symmetrix storage. I was going over the settings and discovered that filesystemio_options was not set (no value given). I changed it to setall per the Oracle documentation for Linux. Shortly after that, our queries suddenly started running longer, and the culprit appears to be disk IO.

I understood that this setting could not cause a problem, and all the Oracle documentation I could find said to set this value to setall in 10.2.0.3. I unset the value and the problem went away. Can someone shed some light on this?

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