Ideally you should distribute i/o evenly across all your disks, and raid5
seems to do just that on first sight. But the overhead it takes to spread
i/o raid5 way is too much for write-intensive systems.
You have 6 drives, so you have some freedom, though more drives
would be even better. I would combine 4 drives into 2 raid1 and keep
2 drives as they are, then put data on one raid1, redo logs on another
(along with archive logs if you're going to run the db in archivelog,
which is recommended), temp on one single drive and rollback/undo
on another single drive (and they better be on different channels). Not
an ideal layout, so if anyone can come up with a better one given
these conditions, I'd like to see it too.
--
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.
"Joe" <joegenshlea_at_attbi.com> wrote in message
news:pOKR8.165885$6m5.138459_at_rwcrnsc51.ops.asp.att.net...
> Cool! A pleasent, helpful and non-condencending response.
>
> It isn't too late for change RAID - I am still in the system analysis
> portion of my project and am testing different configurations. I am a one
> person shop I have full control! I think RAID 5 works well with SQL server
> because you don't have control of tablespaces and datafiles like you do in
> Oracle. I would like some fault tollarance above restoring backup tapes,
> given this, what do you recommend for disk configuration?
>
> Here is my current situation with hardware:
>
> Dual AMD athlonn MP 2000+
> 2 Gigs DDR Ram
> RAID (PCI) controller that supports 4 devices with 32MB RAM mounted (Adaptec
> 2400A)
> 6 Western Digital 80 Gig (8MB cache) ATA/100 disks
> Total Flexibility!
>
>
> Anyone is welcome to submit a vote to optimize hardware configuration for
> Oracle!
>
>
> "Howard J. Rogers" <dba_at_hjrdba.com> wrote in message
> news:af7s4g$44d$1_at_lust.ihug.co.nz...
> > Hi Joe,
> >
> > You seem to have had a run of bad luck with the responses you;ve received.
> >
> > First, if it were that hard to use Oracle effectively, I'd be out of a job
> > teaching people to do it. It's not hard, the responses you've receoved are
> > atypical, and you're on the right lines.
> >
> > Bumping up sort_area_size to extremely large levels within the session is
> a
> > good move, actually, because nobody gets ANY sort_area_size until they
> > actually use it, at which point it grows up to the maximum specified by
> that
> > parameter. At the end of the sort, it shrinks right back down to zero.
> > Unfortunately, it's the case that the memory is often not returned back to
> > the operating system, merely freed within the memory space allocated to
> > Oracle. I haven't actually tested it on Windows... but it would be easy
> > enough to do. Call up Task Manager, and look at the 'Performance' tab as
> the
> > sort proceeds. If the memory is going to be released back to the O/S,
> you'll
> > see the graph rise and then drop back. Also, though, keep an eye on how
> much
> > paging Windows starts doing. If your huge sort_area_size induces extra
> > paging, then that's a BAD thing!!
> >
> > 1b might be a bit ambitious... but test it and see. If it comes back to
> the
> > box after the sort, you've done the right thing. If it doesn't, re-think.
> >
> > Bump up your degree of parallelism, too. I was testing a 24-processor
> > solaris box the other day. Got my degree of parallelism up to 3000!!
> That's
> > going way over the top, though. On a dual-processor box, try bumping it up
> > to 4 or 8. Should be perfectly acceptable.
> >
> > Nologging is fine for create index.
> >
> > RAID 5 isn't. But I guess you can't do much about that! (And it's not the
> > total and utter evil it's made out to be, either).
> >
> > You are, in short, on the right track. A bit more parallelism, and go easy
> > with sort_area_size in respect of possible additional paging. Otherwise, I
> > can't think of an awful lot more than you can do.
> >
> > And don't use SQL Server. Oracle is just fine and dandy!!
> >
> > Regards
> > HJR
> >
> >
> >
> > "Joe" <joegenshlea_at_attbi.com> wrote in message
> > news:d9HR8.139197$nZ3.58364_at_rwcrnsc53...
> > > Hi,
> > >
> > > Environment: Oracle 9i running on Windows 2000.
> > > Hardware: Dual AMD, 2 Gig Ram, RAID 5 disk array (ATA/100)
> > > Application: Datawarehousing
> > >
> > > I am process of evaluating Oracle 9i and SQL server for a datawarehouse
> > > application and have some questions on how to tune 9i to maximize
> > > performance on index building and sorting in general.
> > >
> > > There is a large fact table (80 million rows) that I am testing in both
> > > environments (SQL and Oracle). I am attempting to build an index on the
> > > table want to insure that I have things set up so that Oracle will use
> as
> > > much memory and processor as possible. When building indexes Oracle is
> > > using about 400MB or the 2 Gigs of RAM and only uses 10%-15% of one
> > > processsor and 0% of the other.
> > >
> > > Here is what I have done so far.
> > > - Created a temporary 4GB tablespace and set it to default for the
> > user
> > > account I use.
> > > - increased the sort_area_size for the session to 1GB.
> > > - specify nologging and paralell 2 in the create index DDLs
> > >
> > > Is this the best I can do to maximize sort procesess?
> > >
> > > Joe
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
>
>
Received on Tue Jun 25 2002 - 10:19:16 CDT
