Re: RAC/how should i store oracle files on a SAN

From: DA Morgan <damorgan_at_psoug.org>
Date: Mon, 01 Aug 2005 20:39:24 -0700
Message-ID: <1122953947.776480@yasure>

Andreas Sheriff wrote:

> "Moe" <mwahidi_at_emanagelaw.com> wrote in message
> news:1122922686.586023.163080_at_g14g2000cwa.googlegroups.com...
> 

>>The thing is that my SAN already have RAID and RAID 10, so do you
>>think it's ok if i have ASM on top of the RAID?.
>>Im thinking of going with raw for the two CRS files and ASM for the
>>rest.
>>
>>Thanks
>>
>>Moe
>>

> 
> 
> Aren't ASM and raid redundant?
> 
> Hardware based RAID's are ALWAYS better than software based RAID's because
> the hardware based RAID has its own CPU. 

Redundant? Not at all. It is important to remember that ASM does a lot more than a simple LVM (Logical Volume Manager). Sure ASM creates disk groups and failover groups but it also load balances when you add and remove disks. RAID isn't going to do that.

ASM will also let you move from one array to another by sequentially adding disk from one and subtracting from the other. RAID won't do that either.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)

Received on Mon Aug 01 2005 - 22:39:24 CDT