Re: Should Redo Log Files be on RAID5 or no???

In article <850tb2$a9i$1_at_news.duke.edu>,   "jennetta" <jennetta_at_hotmail.com> wrote:
> Should Redo Log Files be on RAID5??? Is there a negative impact on
> performance?
> How about the database files? Oracle Server files? Operating system
files?
>
> Any suggestions/experiences regarding performance will be appreciated.
>
>

The answer is "it depends." Some people will say RAID5 is the worst thing you can do. Yes, all things being equal (all things are never equal) RAID5 will extact some performance penalty on write operations, due to the need to compute parity data. On the other hand, read operations can actually be enhanced by the parallelism, and this gets better with more disks in the array. RAID5 implemented in hardware with a fast, caching RAID controller will not cause nearly the performance degradation as it would if implemented in software.

Since the performance penalty is on write operations, there should be no reason not to put read-only and low-write files (operating system, Oracle software, etc) on it. Heavy write files like logs would be best placed on RAID1 (disk mirroring) but your activity level may be low enough that there is no practical reason not to put them on RAID5.

--
Ed Stevens
(Opinions are not necessarily those of my employer)

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Before you buy. Received on Thu Jan 06 2000 - 07:19:45 CST