Re: Raw Disk Partition vs. Unix File System (Oracle 6)

In article <1993Aug23.162749.22979_at_exlog.com>, lparsons_at_exlog.com (Lee Parsons) writes:
|> In article <CC7IoC.FtA_at_vistachrome.com> andy_at_vistachrome.com writes:
|> >cafe_at_cbnewse.cb.att.com (richard.dib) writes:
|> >>- Does anybody have any experience with Oracle using a raw disk partitition
|> >> instead of the Unix file system? Could you share your experiences?
|> >

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I suggest you get a copy of "Making the Decision to use UNIX Raw Devices", Number 2 in the Oracle NPST Technical Monograph Series by Cary V. Millsap, Oracle National Product Specialist Team (cmill_at_us.oracle.com). It lists the following as prerequisites for going raw:

Use raw devices only if the UNIX operating system does not offer the capability for direct I/O through the UNIX filesystem.

Use raw devices for Oracle files only if the site has sufficiently brutal transaction and query volume that disk I/O is the performance bottleneck.

Use raw devices for Oracle files only if the site has at least as many raw disk sections as it will have Oracle tablespaces.

Use raw devices for Oracle files only if the site has enough disk space that it can afford over-allocation of small Oracle tablespaces.

Use raw devices for Oracle files only if the site has multiple experienced Oracle and UNIX administrators.

From the summary:

Using raw devices can help performance at the margin in some installations, but raw raw I/O will not benefit most Oracle sites.

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