Re: RAID 5 or 5 hard disks?

My experience has been that Raid 5 gives you a large performance hit. It may be true that if you have enough disks for raid 5 then it is okay. But people who tend to use raid 5 (not all) are looking at the bottom line in terms of raw cost and not in terms of the cost of poor performance. Thus they tend to buy the minimum (e.g. 3 disks) and not more (like 10). Jim

"Niall Litchfield" <n-litchfield_at_audit-commission.gov.uk> wrote in message news:90qba0$3n$1_at_soap.pipex.net...
> Hi
>
> Raid 5 is fine (so long as you have sufficient disks). However redo and
> archive logs should always be mirrored. This suggests that you should have
> as well as the raid 5 volume at least one mirrored pair for logs and
> preferably at least 2. You can then put the os on one mirrored pair the
 logs
> on another and the data on your raid5 set.
>
> You will always get better performance from striped and mirrored disks but
> this tends to be expensive compared to raid5.
>
>
> --
> Niall Litchfield
> Oracle DBA
> Audit Commission UK
> "Allen" <allenh_at_starbase.neosoft.com> wrote in message
> news:BD71F762829CE2EA.D22E5AC688FEA19C.C4951E8FAF1A6749_at_lp.airnews.net...
> >
> > I've always installed my databases with indexes on one HD, RBS on
 another,
> > etc.. now I'm in a new environment where they want to use a Raid 5 disk
> > box that will have all my datafiles in the same volume. Supposedly the
> > RAID stuff will take care of spreading out the files on different HDs.
> > Is this cool, or should I still insist on several different HDs within
 the
> > Raid 5 environment?
> >
> > thx.. Allen
>
>
Received on Fri Dec 08 2000 - 09:15:29 CST