Re: Filesystem vs. Raw IO

> NetApp disk UFS filesystem: 48 sec
>
> NetApp disk raw space: 3 min 7 sec
>
>
>
> What should I be looking at?  Why such a big difference?

What if you set your filesystemio_options to direct or setall in your UFS
configuration? That way filesystem buffering for read-ahead purposes won't
be used. Also set the db_file_multiblock_read_count to 1MB (128 for 8K
blocks) in both configurations - that way raw IO has more chance to compete.

Tanel.


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