RE: ORION num_disks

From: Allen, Brandon <Brandon.Allen_at_OneNeck.com>
Date: Fri, 12 Sep 2008 10:54:22 -0700
Message-ID: <04DDF147ED3A0D42B48A48A18D574C450D542939@NT15.oneneck.corp>


No prob - I know the documentation doesn't make it very clear. One thing to be careful with - most filesystems are cached, so you'll probably get unbelievably good numbers from Orion. The way I usually workaround this is to create files for testing that are much larger than my RAM, and clear the OS buffer cache prior to testing. You could also try playing with the cache_size parameter for Orion, but that never seemed to do much for me. Hopefully in a future version of orion, they'll support using directio on a filesystem where supported by the OS, just like the Oracle database does (e.g. filesystemio_options=directio).  

One more thing to beware of - if you configure orion to run write tests (it does read-only by default with the simple/normal type tests), it will destroy any data in the specified test files - so make sure you don't have it pointed to anything you want to keep, like a real Oracle datafile.  

Regards,

Brandon  

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Received on Fri Sep 12 2008 - 12:54:22 CDT

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