Re: XP256 Disk Striping for an Oracle 8.1.7 DataWarehouse
Date: Mon, 23 Jul 2001 23:47:57 GMT
Message-ID: <3B5CB790.A4F086C0_at_parallon.com>
When you say 'stripe size' do you mean LVM striping? I played around with
stripe sizes before and I have not seen much of a difference to be honest
with you. As far as one large group, I would suggest breaking it to few
groups for organizational sake. Four volume groups sounds like a good
number but it's really up to the admin, just don't make too many small
ones cause you loose flexibility.
Tom Lewis wrote:
> I have a 400GB Oracle 8.1.7 data warehouse deployed onto a XP256. The
Thanks,
George
> warehouse often needs to full table scan tables of c50GB and uses
> parallel execution to achieve this. The database is using 8K blocks
> and the DB_FILE_MULTIBLOCK_READ_COUNT is set to 16.
>
> The XP256 has been configured with RAID 5 and a stripe size of 256K.
> Its 36 disks have been divided into 8 logical volumes of 4-6 disks
> each with different tables or indexes assigned to each logical volume
> to avoid contention.
>
> I really need some help on two fronts.
>
> What is the optimal relationship between the DB block size and the
> stripe size. Currently, I assume that the database will read 32 blocks
> off disk 1 and then 32 off disk 2 etc. etc. That does not sound very
> parallel to me. Should the stripe size be smaller?
>
> Secondly, is it necessary to divide the XP256 into different volumes
> for different purposes or is a larger single volume a better approach?
>
> Many thanks in advance
>
> Tom
Received on Tue Jul 24 2001 - 01:47:57 CEST