My workplace is having a debate on what to use for a file system/disk
management perspective for RAC. I would like to know what others have
built their RAC clusters on, are more people using ASM or GPFS. I'm
not a DBA, but do support Unix and lean towards using ASM. I've read
several white papers and documents on the whole subject and ASM just
seems to have many benefits to the DBA. I really would like to get
other's opinions. GPFS is not really needed, but was suggested. This
cluster would be running on AIX 5.3/Oracle 10g2/Rac on EMC SAN. We
would start with 2 data base instances and then grow to maybe 10.

Hi,

I guess this WP will help you understand few customers opinion.


http://www.oracle.com/dm/technologie...TEMBER2005.PDF

..Raju

You already have EMC SAN with external redundancy. So I guess you
don't use ASM for redundancy. Using GPFS would be a better choice
since you have more control on your system. However, licenses of most
commercial cluster file systems are expensive. If cost is an issue,
you may want to consider the free OCFS on Linux. I'm using it for 10g
RAC on RHEL AS and HDS (Hitachi data system) and it works fine.

tangdba@gmail.com wrote:
> You already have EMC SAN with external redundancy. So I guess you
> don't use ASM for redundancy. Using GPFS would be a better choice
> since you have more control on your system. However, licenses of most
> commercial cluster file systems are expensive. If cost is an issue,
> you may want to consider the free OCFS on Linux. I'm using it for 10g
> RAC on RHEL AS and HDS (Hitachi data system) and it works fine.

We also use OCFS but we are facing a problem - it SEEMS that Oracle is
not very actively developing and supporting OCFS. While OCFS version 1
is certified with RAC, OCFS version 2 is not and it does not look like
it is going to be soon.

I capitalized seems above because it is hard to get commitments out of
Oracle concerning their future strategy.

OCFS version 1 unfortunately does not run on all platforms, I don't know
about AIX.

It seems that Oracle themselves are pushing ASM as hard as they can -
no wonder because it gives them control over yet another layer of the
customer system.

When you take ASM, make sure that you store your ASM configuration
in some external safe place. If your system blows up, you must be able
to reconfigure your ASM before you can restore your database.

Yours,
Laurenz Albe

We are locked into AIX, so Linux is out of the question for now anyway.
I suppose the benefits of using ASM are not that big of a deal to the
DBA?
I/O is spread across all disks to help eliminate hot spot
Automatic distribution of storage amongst a disk group
Lower cost in my case
Oracle seems to want to move in this direction

On Thu, 30 Mar 2006 04:25:40 -0800, Karma wrote:

> We are locked into AIX, so Linux is out of the question for now anyway.
> I suppose the benefits of using ASM are not that big of a deal to the
> DBA?
> I/O is spread across all disks to help eliminate hot spot
> Automatic distribution of storage amongst a disk group
> Lower cost in my case
> Oracle seems to want to move in this direction

You are asking wrong questions. To decide whether to use ASM or not, you
should ask yourself whether it is possible to access data structures
within ASM with other means or just by oracle. Can you use tar on ASM
files or not? ASM is just a volume manager. Compare it with the native
volume managers for EMC and AIX and decide which one is a better fit for
your needs.

--
http://www.mgogala.com

On 2006-03-30, Mladen Gogala <gogala@sbcglobal.net> wrote:
> On Thu, 30 Mar 2006 04:25:40 -0800, Karma wrote:
>
>> We are locked into AIX, so Linux is out of the question for now anyway.
>> I suppose the benefits of using ASM are not that big of a deal to the
>> DBA?
>> I/O is spread across all disks to help eliminate hot spot
>> Automatic distribution of storage amongst a disk group
>> Lower cost in my case
>> Oracle seems to want to move in this direction
>
> You are asking wrong questions. To decide whether to use ASM or not, you
> should ask yourself whether it is possible to access data structures
> within ASM with other means or just by oracle. Can you use tar on ASM
> files or not? ASM is just a volume manager. Compare it with the native
> volume managers for EMC and AIX and decide which one is a better fit for
> your needs.
>

If you have an interest in treating your databases like
simple collections of files that you can tar up and drop down
anywhere in your environment, ASM is probably not for you. Using
ASM it seems will commit you to using it throughout your
environment (dev, test, etc).

--
Sure, I could use iTunes even under Linux. However, I have |||
better things to do with my time than deal with how iTunes doesn't / | \
want to play nicely with everyone else's data (namely mine). I'd
rather create a DVD using those Linux apps we're told don't exist.

Karma wrote:
> My workplace is having a debate on what to use for a file system/disk
> management perspective for RAC. I would like to know what others have
> built their RAC clusters on, are more people using ASM or GPFS. I'm
> not a DBA, but do support Unix and lean towards using ASM. I've read
> several white papers and documents on the whole subject and ASM just
> seems to have many benefits to the DBA. I really would like to get
> other's opinions. GPFS is not really needed, but was suggested. This
> cluster would be running on AIX 5.3/Oracle 10g2/Rac on EMC SAN. We
> would start with 2 data base instances and then grow to maybe 10.

Given that you already have an EMC my recommendation would be to
create one or more LUNs with block devices (raw) and use ASM to
manage it.

Oracle may not continue to support OCFS and going that direction
involves risks not worth taking.
--
Daniel A. Morgan
http://www.psoug.org
damorgan@x.washington.edu
(replace x with u to respond)

Laurenz Albe wrote:

> We also use OCFS but we are facing a problem - it SEEMS that Oracle is
> not very actively developing and supporting OCFS. While OCFS version 1
> is certified with RAC, OCFS version 2 is not and it does not look like
> it is going to be soon.

Can you please explain this comment given the following?

http://oss.oracle.com/projects/ocfs2/

Thanks.
--
Daniel A. Morgan
http://www.psoug.org
damorgan@x.washington.edu
(replace x with u to respond)

DA Morgan wrote:
> Laurenz Albe wrote:
>
>> We also use OCFS but we are facing a problem - it SEEMS that Oracle is
>> not very actively developing and supporting OCFS. While OCFS version 1
>> is certified with RAC, OCFS version 2 is not and it does not look like
>> it is going to be soon.
>
> Can you please explain this comment given the following?
>
> http://oss.oracle.com/projects/ocfs2/
>

Hello,
since I had the same problem, I'm jumping in.

From the link you provided:

"OCFS2 certification with Oracle 10g Release 2 RAC on Linux x86, x86-64,
Itanium and Power is currently in progress.
Upon completion of certification, Oracle will provide Unbreakable Linux
Support for OCFS2 on 10g Release 2 RAC. "

and metalink note #279069.1 on certified filesystems (last modified this
week):

"Note: OCFS2 certification with Oracle products is currently in progress."

Regards

--
Fabrizio Magni

fabrizio.magni@mycontinent.com

replace mycontinent with europe