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RE: RAC & RAW Question

From: Powell, Mark D <>
Date: Sat, 23 Apr 2005 08:09:09 -0400
Message-ID: <>

The rules for working with raw partitions vary by the capabilities of the logical volume manager provided with the OS. With Sequent we could allocate a new raw partition on the fly and immediate connect it to Oracle. With AIX we have to shutdown everything that uses the file system [for want of a better term] and then allocate another raw partition. Some system may support extending raw partitions while others do not. Traditionally the ability to extend a raw partition dynamically did not exist. Heck, it wasn't all that long ago that the size and number of raw partitions you could create was almost a physical property of the disk. On some systems raw partitions are fully as easy to manage as a traditional UFS file system. It all depends on the LVM and if the administrator knows how to use if properly.

HTH -- Mark D Powell --

-----Original Message-----

From: [] On Behalf Of Stephen Andert
Sent: Friday, April 22, 2005 5:40 PM
Subject: RAC & RAW Question

Hi all,=20

I am working on getting RAC set up. It is sr mgmt's idea and I'm not sure that it will provide what they think it will.

I have a question about growing with RAW.

I read in a book that RAW partitions cannot be extended. After discussing this with my friendly neighborhood SysAdmin team, they have told me that growing a RAW partition/device is not a problem. They don't even think I need to bring down the database.

My questions are:

Q1. Is it possible that the author was speaking in general terms and that in my environment, we have an OS, etc that allows this (AIX, EMC)?

Q2. Is it that the OS can do it, but the database cannot recognize it? (I thought a alter database datafile ... RESIZE would work)

Q3. Can anyone point me towards a best practices with RAW white paper?

Q4. Does anyone have any pointers towards converting a cooked database to RAW? It is large enough that export/import will take more time that I think we will get approved for. We are theorizing that if we "reshape" the database to tablespaces with single files that match the sizes of the RAW devices we will be getting, that an RMAN alternate node restore with file rename will work. Thoughts or comments on this?

-- Received on Sat Apr 23 2005 - 08:14:13 CDT

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