Re: ASM on SAN

From: Stalin <>
Date: Wed, 24 Feb 2010 15:01:36 -0800
Message-ID: <>

We are mostly Solaris shop. The way we carve out LUNS is Stripe and Mirror Everything (same) with all available disks in the storage doing hardware RAID 1+0 and create a big virtual disk, then create a LUN for DATA and FRA with appropriate sizes. We are not using ASM yet but that's what we do with our single instance databases. From what i read here is, the above setup can limit IO throughput on a single LUN even though they are backed by several disks. Can anyone explain why that would be.


If you don't mind could you share the parameters that can limit this in Solaris.


On Mon, Feb 22, 2010 at 12:22 AM, LS Cheng <> wrote:
> Use option 1, if you have redundancy in SAN then there is no point to use
> ASM mirroring. I have only used ASM redundancy once in a JBOD storage array
> and many times for extended clusters.
> Use multiple LUNs since there are some parameters (at leats in Solaris)
> which can limit number of I/O requests to a LUN so if you have few LUNs you
> are actually lowering your S.O I/O throughput. Also as others already
> pointed out if you use a large LUN and you plan to follow ASM best practice
> then each time you want to grow you are increasing your ASM Disk Group size
> by two which can be a waste of space. I have implemented in a few customer
> two standard LUN sizes for small/middle and large databases.
> Thanks
> --
> On Sun, Feb 21, 2010 at 8:16 PM, Chen Shapira <> wrote:
>> Hi Oracle-L,
>> I'm preparing to install ASM using our EVA storage and I'm trying to
>> decide how many volumes to request from my storage manager.
>> There are two configurations we consider:
>> 1) Ask for two volumes - one for data files, the other for flashback,
>> archive logs, backups, etc. Then run ASM with external redundancy and
>> external striping. Let EVA do the RAID thing for us.
>> 2) Ask for multiple data volumes and multiple backup volumes.
>> Configure ASM to do its own striping. Since EVA will do its own
>> stripe+mirror thing, we'll have double striping.
>> I'm leaning toward the first option since it seems more manageable.
>> Does anyone on the least have a good reason to go with the second
>> option? I'm worried that I'm missing something, because all ASM papers
>> natually assume there will be multiple ASK "disks".
>> Chen
>> --

Received on Wed Feb 24 2010 - 17:01:36 CST

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