Re: ASM LUN sizes and number of disks

Hrishy,

The number of spindles are dependent on the required IOPS. In theory a 15K drive (Fiber channel) can sustain around 150-180 IOPS. So if you are short on IOPS going to higher capacity disks will make your database much slower (in your new/upgraded config you are essentially cutting the I/O capacity by half) .

Look at your AWR/Statspack to figure out your IOPS requirement and make your decision on moving to 200G drives.

Best Regards,
K Gopalakrishnan
Co-Author: Oracle Wait Interface, Oracle Press 2004 http://www.amazon.com/exec/obidos/tg/detail/-/007222729X/

Author: Oracle Database 10g RAC Handbook, Oracle Press 2006 http://www.amazon.com/gp/product/007146509X/

On Thu, Nov 6, 2008 at 11:30 PM, hrishy <hrishys_at_yahoo.co.uk> wrote:
> Hi
>
> We have a 200Gb database and there are 6X50gb luns comprising a diskgroup called dataDG
>
> Since my database is growing around 100gb per year i am planning to add two 200Gb disks to the above diskgroups and simulatenously drop the 6 50gb disks off.
>
> I understand reblance would trigger in my case and i am planning to add 200gb disks to the luns and increase the diskgroup sizes.
>
> My question is there a formula or a rule of thumb to determine the number disks and the size given a database size and estimated growth rates?
>
> regards
> Hrishy
>
>
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

--
http://www.freelists.org/webpage/oracle-l