Re: Disks not detected during ASM setup 11gR2

From: sundar mahadevan <>
Date: Mon, 3 Jan 2011 10:50:58 -0500
Message-ID: <>

Hi Jeremy,
I highly appreciate your patient response. Thanks to the list, I already have ASM running. But I need to make some changes to the logical volume as per your reply. I will definitely go through the documentation and make myself familiar. Thanks to one and all.

On Sun, Jan 2, 2011 at 10:50 PM, Jeremy Schneider <> wrote:

> Hello Sundar -
> Oracle has very good documentation for the database and ASM. I think
> that you will find most of the answers you are looking for in those
> documents.
> For example, the first sentence of chapter 1 in the ASM admin guide
> says: "Oracle ASM is a volume manager and a file system for Oracle
> database files that supports single-instance Oracle Database and Oracle
> Real Application Clusters (Oracle RAC) configurations." As you can see
> from this sentence, ASM *is* a filesystem and volume manager - so
> generally you would give it raw disks or partitions and it would work on
> those.
> I would suggest reading these docs since you will find many answers
> there. Also, most people on this particular list assume familiarity
> with the introductory docs... you will find a lot more help after you're
> familiar with them.
> To answer your most recent questions:
> 1) There is no "mount point" or "fstab" involved with ASM at all.
> 2) There is no filesystem involved with ASM at all. (There are some
> advanced tricks to run ASM on top of a filesystem, but this is not
> normal and would only be used in rare circumstances.)
> 3) Logical Volumes do not have mount points. You can create a logical
> volume and change the device node so that the oracle user can access it
> - and you will trick ASM into thinking it's a disk. There are a number
> of companies that do this on production systems for various reasons, but
> unless you *need* to then I don't think you should use both LVM and ASM
> together.
> 4) The best place to start learning is the Oracle documentation itself.
> You can start at
> You don't need to be an expert, but you do need to have a very good
> understanding of each of these terms: disk, LUN, unix device, partition,
> volume manager, filesystem.
> You're on the right track - I've helped lots of people get oracle and
> ASM running on their laptops and I think it can help a lot with learning
> how everything works. :) Good luck!
> -Jeremy
> sundar mahadevan wrote:
> > Hi Saurab,
> > Thanks for your input. I tried to search for setting up asm without
> > asmlib but dint find anything on google. I presently do not have grid
> > control asm binary installed yet and hence no asm instance to do
> > select path from v$asm_disk. Please help me with the following.
> >
> > 1) Is the mount point to be owned by user oracle or the device to be
> > owned by user oracle. Do you have the fstab entry for this?
> > 2) Can there be a filesystem underneath like ext3 or no?
> > 3) Can a logical volume with a mount point owned by oracle be sufficient
> ?
> > 4) Are there any blogs, links or documents that I can make use of to
> > achieve this?
> >
> > Highly appreciate your help.
> --
> +1 312-725-9249
> Jeremy Schneider
> Chicago

Received on Mon Jan 03 2011 - 09:50:58 CST

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