RAID5 is fine for read-intensive systems, like DW, but exhibit awful performance
on write-intensive systems (OLTP). That's due to the way the data is written
and the amount of extra work the controller has to perform (and if it's software
RAID5, then it's all worse because you are wasting main CPU for this overhead).
--
Vladimir Zakharychev (bob@dpsp-yes.com) http://www.dpsp-yes.com
Dynamic PSP(tm) - the first true RAD toolkit for Oracle-based internet applications.
All opinions are mine and do not necessarily go in line with those of my employer.
"pankaj" <pankaj_at_ladbrokes.com> wrote in message news:3d0e07c1_1_at_corp-goliath.newsgroups.com...
> Hi ,
>
> I have questions regarding VXFS on oracle 8.1.6 on solaris 2.7.
>
> I created a volume group under raid 5 and then created a VXFS filesystem on
> this volume. I was moving from a UFS file system at the same time changing
> the Oracle character set.
>
> Is it a good idea to create a volume with raid 5 and then create a vxfs file
> system. I did not see much improvement.
>
> Is it also possible for you to send me a copy of the performance tests
> please
>
>
> Pankaj.
>
>
> "Knut Talman" <knut.talman_at_mytoys.de> wrote in message
> news:3D07941D.99D4425B_at_mytoys.de...
> > > Could you provide more detail, if not in the group to my e-mail
> > > address.
> > > We have an customer on Solaris 2.6 that is using the Basic Edition of
> > > Veritas that comes with Solaris and the customer needs to be convinced
> > > he should buy the Advanced Edition. Using raw devices is not really an
> > > option: the database(s) grow tremendously fast due to lack of
> > > procedures to archive historic data (this is a 3rd party app, and we
> > > can not address that issue).
> >
> > Your customer won't regret the decision (at least we didn't...)
> > To give more details:
> >
> > We measured OS operations like copying a large file, copying multiple
> smaller
> > files, removing files and database operations like insert, update, delete.
> >
> > What we determined was a significant advantage of VFS vs. UFS (of course).
> Also
> > database operations where faster but when we used QIO it gave our database
> test
> > another boost of about 50-75%. I can not certify Veritas' performance test
> where
> > they had a performance enhancement of 300-400%. I'll send you their
> document by
> > mail.
> >
> > The intention of our tests were huge problems w/ I/O wait. During load
> peaks we
> > had I/O waits of up to 90%. After some tuning (75% I/O wait) we bought new
> > hardware (SAN) which reduced I/O wait to 20%. With QIO we have a max I/O
> wait of
> > 10%.
> >
> > Regards,
> >
> > Knut
>
>
>
>
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Received on Tue Jun 18 2002 - 12:48:38 CDT
