From: D'Hooge Freek <>
Date: Sun, 21 Feb 2010 22:30:50 +0100
Message-ID: <>


I normally use multiple luns from the san to construct the asm diskgroups. The size of the luns depends on the initial size of the database and the expected growth (a question which is most times answered with: no idea). For instance, for a db with an initial size of 100 GB and a yearly growth of 20GB, I would setup 4 luns of 30GB (initial size + 1 year). When more space is needed, I can add additional luns of 30GB. If I would have used 1 lun of 120 GB, then in year 2 I would have needed to add a second lun of 120GB (best practice to keep all luns in a diskgroup the same size) or I needed to size the lun directly to cope with, for instance, 5 years of growth.

Also, in most cases I have multiple databases on the same server. So when I keep the lun size the same for all asm diskgroups (or maybe divide them into data and backup) I can easily play with them. Removing them from one database and add them to another.


Freek D'Hooge
Oracle Database Administrator
tel +32(0)3 451 23 82

From: [] On Behalf Of Chen Shapira [] Sent: 21 February 2010 20:16
To: oracle-l
Subject: ASM on SAN

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".


-- Received on Sun Feb 21 2010 - 15:30:50 CST

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