Re: Help: Create file system on a shared disk

From: Steve Howard <>
Date: Thu, 21 Feb 2008 06:21:25 -0800 (PST)
Message-ID: <>

On Feb 21, 8:39 am, wrote:
> Dear Group,
> Are there anybody here also storage group/SAN box expert?
> We are building a RAC on linux (10202). We have a huge lun(1000G),
> connected to all the nodes. I need a file system just for one nodes,
> so I created a partition out of this Lun(100G) and mounted this
> partition only to node 1(Lets say partition 1). And leave the rest of
> the lun for a ASM disk.
> Our consultant tells me that this will cause a lot of problems. The
> asm filess on another partition on the same lun will be corrupted, and
> OS will be corrupted.
> Is this true? While I understand other node will see partition 1,
> they do not have mount point to this partition, and how can this
> corrupt ASM disk on another partition, how can this further to corrupt
> my OS?
> Your help is highly appreciated.

I'm not sure what kind of SAN you have, but I don't see how this will "corrupt the OS".

ASM uses raw devices, carved out of disk partitions (originating on the LUN(s)). You can create multiple partitions out of a single LUN. If you have (say) ten partitions created out of a TB LUN:

  • each 100GB
  • one of them used for a filesystem
  • the other nine used as disks under nine raw devices used by ASM

These won't impact each other, at least logically/data integrity wise. Depending on how the actual spindles are configured under the LUN, you may have performance problems, though.

What specifically did the consultants say as to how it would "corrupt the OS"...genuinely curious...

HTH, Steve Received on Thu Feb 21 2008 - 08:21:25 CST

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