Re: Unix File System vs. Raw Devices

In article <6ip15b$poc$1_at_sunrise.pg.gda.pl>#1/1,   "Piotr Kolodziej" <pkol_at_otago.gda.pl> wrote:
>
> >In Sybase on Unix, you always did all of your device/database creation on
> >raw devices because the Unix FS buffers its writes thereby eliminating any
> >guarantee that your log writes actually made it to disk. What's the story
> >with Oracle 8 in this context? From the training that I've gone through
> >for Oracle, everything seems to be so file/pathname oriented, that it
> >doesn't seem like raw devices are even an option although I'm told they
> >are.
>
> I believe, that when Oracle background processes writes
> to files then it really writes. There's the flush function which
> empties FS buffers. That is in unix world.
> However, on NT filesystem (NTFS) it may not be true...
> In Oracle all caching is based on SGA shared memory. So there's
> no need to use FS caching anf flush function may be performed.
>
> Using RAW devices gives you a bit better performance but
> if you want to run Oracle for example in archivelog mode,
> you'd better use filesystems.
> Every restore/recovery method is much much easier when you use
> unix filesystem.
>
> Regards,
> Piotr
> pkol_at_otago.gda.pl
>
>

Although I have used RAW in the past -- with the new autoextend tablespaces (datafiles) FS files seem pretty nice when you run low on space...

Daryl

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