Re: Cluster File System Versus ASM for RAC Deployment in Production?... Pros & Cons

I had to setup OCFS2 in a customer for the these reasons:

they didnt want to assign a big lun for a small files such as voting and ocr

they used utl_file extensively, nfs was not an option because it would become a SPOF

they didnt have a backup agent so backing up ASM to tape was not an option and to to able to run backups from all fours nodes a CFS must be used

thanks

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LSC


On 12/6/07, Matthew Zito <mzito_at_gridapp.com> wrote:


>

>

> I always recommend using both ASM and a CFS, where appropriate.  For

> example, on Linux systems, where there is a free, Oracle-supported CFS

> (OCFS2), I recommend making a small OCFS2 filesystem (or two) for storage of

> OCR and voting files.  Then, make the primary datafile/index/log storage on

> ASM.  Optionally, they can then have a large dump or backup filesystem that

> is OCFS2, or NFS - but I always recommend keeping an archive location

> outside of ASM, so if the ASM instance won't start up, you can at least get

> to your archive logs, and presumably you're doing backups or a standby

> database somewhere.

>

> The reason for using both ASM and CFS on Linux is because dealing with

> multiple block devices for the various OCR and Voting devices is annoying

> and complex, and typically you'll end up wasting a lot of disk space (i.e.

> allocating an 8GB lun for a 100MB ocr device).  By using a clustered file

> system, you can put multiple objects on the one disk, and if necessary,

> store other things there.  However, OCFS2 has no capability for growing

> filesystems, creating situations where using OCFS2 for datafiles means

> increasing the number of mounts over time, which gets messy.  ASM solves

> that problem for you by doing very basic striping.

>

> Thanks,

> Matt

>

> --

> Matthew Zito

> Chief Scientist

> GridApp Systems

> P: 646-452-4090

> mzito_at_gridapp.com

> http://www.gridapp.com

>

>

>

> -----Original Message-----

> From: oracle-l-bounce_at_freelists.org on behalf of Dan Norris

> Sent: Thu 12/6/2007 7:51 AM

> To: VIVEK_SHARMA_at_infosys.com; oracle-l_at_freelists.org

> Subject: Re: Cluster File System Versus ASM for RAC Deployment in

> Production?... Pros & Cons

>

> Personally, I'd choose ASM and recommend it to all my customers. This is

> partly because: 1) Oracle recommends it, 2) if Oracle recommends something,

> they generally support it better than things they don't recommend, 3) it

> doesn't cost extra money, and 4) I think ASM is a fine product that does its

> job well (admittedly better in 11g than 10g, but that's not your question).

>

> I think that using a CFS requires training for system admins while ASM

> would also require training, but possibly for the DBAs instead of the

> sysadmins. Typically, I still see ASM being managed by DBAs even though it

> really isn't a database. Many companies have the DBAs manage anything with

> the word Oracle stamped on it.

>

> For docs or links, see otn.oracle.com/asm.

>

> Dan

>

> ----- Original Message ----

> From: VIVEK_SHARMA <VIVEK_SHARMA_at_infosys.com>

> To: "oracle-l_at_freelists.org" <oracle-l_at_freelists.org>

> Sent: Wednesday, December 5, 2007 9:08:21 PM

> Subject: RE: Cluster File System Versus ASM for RAC Deployment in

> Production?... Pros & Cons

>

>

>

>

>

>

>


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