Re: Oracle and striping??

Craig Munday wrote:
>
> All,
>
> A couple of months ago I asked a question about what is an appropriate RAID
> level to run for an Oracle server. A lot of people wrote back to me and
> suggested RAID 0+1, which is what I excepted.
>
> In terms of striping, can any one recommend how to configure the disks into
> stripe sets for an Oracle datbase. For example, should there be one stripe
> set which contains the redo, rollback, data and indexes? Or should the
> redo be separated from the other files? What about rollback segments,
> should these be separated?

The more you split the better performance you'll get. So if you can afford multiple controllers and HD's this would be the best way. But in most cases it's to expensive. 'cause RAIS strips your fils over several disks leaving data, indexes and rollbacks on the same stripe may result in a performance that reaches your aims. One thing you've to remember: disable your writing cache!!! Switch to write through to ensure that your transactions are always realy written to HD and not only in cache. Otherwise you'll fall into inconsistencies in case of power failures.
One other thing you should look upon is to set your db-block size to stripe-size.  

> I can see benefits for both but lack the experience with striping to know
> which is the better choice.
>
> I am tending towards puting the redo log in its own strip set becuase of the
> writing that is performed to these files.

Yes, that's fine. It' also recommended by oracle.

>
> Cheers,
> Craig Munday

-- 
Regards

Matthias Gresz    :-)