Re: RAID 5 or 5 hard disks?

Good question -

The answer is that a very large number of systems are just small office systems that have one little black box with a couple of CPUs, 5 discs at 9GB, running NT.

With minimal tuning they can run perfectly well despite a nominal (rarely actual) overhead of 200% on writes, because Oracle simply avoids lots of write requests (even on logs).

Unless the number of spindles is too low, a simple RAID-5 system on the typical 5-disk set-up will perform perfectly adequately for a low-stress system.

(See my book - Chapter 10 Files, Raw and RAID).

--
Jonathan Lewis
Yet another Oracle-related web site:  http://www.jlcomp.demon.co.uk

Practical Oracle 8i:  Building Efficient Databases

Publishers:  Addison-Wesley
Book bound date: 8th Dec 2000
See a first review at:
http://www.ixora.com.au/resources/index.htm#practical_8i
More reviews at: http://www.jlcomp.demon.co.uk/book_rev.html



Niall Litchfield wrote in message <90tbvl$jlo$1_at_soap.pipex.net>...


>I agree that that is what happens, and that it is wrong. however I'd be

>interested to know exactly what sort of performance hit one gets from a

>machine with data & indexes on raid 5, but with well tuned memory

 structures


>etc.

>