Re: Configuring Oracle on RAID 5

Am I being thick, or isn't RAID-1 a single disk, and RAID-2 a mirror, since RAID-5 is 5 disks?

"Fred A G" <nospam_at_allowed.localhost> wrote in message news:y2fr6.1170$341.4161_at_nntpserver.swip.net...
>
> ""Anurag Minocha"" <aminocha_at_herold.com> wrote in message
> news:EBBA6D3A81229C42981E3AEA79BF5A4E111233_at_jshemail.herold.com...
> > Hi,
> > I was wondering that since RAID5 creates one logical volume of disk
 across
> > multiple drives there is no need to have multiple copies of control
 files
> > and also multiplexing redo logs is not required.
> >
>
> Raid protects against single-disk failures, nothing more. Have at least
> two or even three independent control file copies. Regarding redo log
> files, if you have very basic requirements (few log groups, no
> archiving(but why!)) then you can have only one raid-1 (mirroring) disk
> dedicated to redo.
>
>
> > I might be wrong ... I am not sure.
> >
> > what care needs to be taken in creating and placing datafiles, redo
 log
> > files and control files on a RAID 5 machine.
> > where can i find more information about Oracle on RAID 5 machines.
> >
>
> To me, this seems backward: to buy disks and other hardware and set up a
> Raid-5 disk array, then figure out what the database physical layout and
> I/O requirements are.
>
> As a very basic setup, I'd say get at least four spindles dedicated to
> Oracle, one of which is for redo (two out of five, if mirroring). Maybe
> add one more for Oracle products software. Think IOPS, not storage
> volume (or, disk is cheap, don't be afraid to "waste" space). Then, if
> one or more datafile needs more IO put them on a Raid-5 or possibly
> better Raid 0+1.
>
> Regards
> /Fad
>
>
Received on Tue Mar 13 2001 - 05:52:28 CST