RE: Oracle RAC backup hardware/software recommendation?

  • From: "Marquez, Chris" <cmarquez@xxxxxxxxxxxxxxxx>
  • To: "David Sharples" <davidsharples@xxxxxxxxx>
  • Date: Mon, 3 Oct 2005 11:12:35 -0400

Dave,

I can not find the document so I have to take that comment back...although I'm 
sure I have seen it?
To be honest, I never did nor tried this.

        ---METALINK
        Doc ID:         Note:252331.1
        Subject:        Update on OCFS for Linux

        ---oss.oracle
        
http://oss.oracle.com/projects/ocfs/dist/documentation/RHAS_best_practices.html 
        For optimal performance, each node should have its own, separate OCFS 
archive log partition. 

However, below are old docs regarding OCFS (arch log) issues...and note I had 
all my problems with (more recent) OCFS version 1.0.12.x or 1.0.13.x.

        ---METALINK
        3146671-OCFS ARCHIVE DESTINATION NOT RESPONDING TO UNIX COMMANDS

        ---METALINK Forum [This one gets ugly]
        Real Application Clusters/High Availablity Technical Forum
        Thread Status: Closed
        Subject: Linux OCFS causes kernel panic on Red Hat AS 

I (gladly) forgot about some of the ugly "all node server hangs" we had when 
doing simple OS commands (ls -l) on OCFS during less than heavily server/db 
load.  It was so bad and we so scared, that no one would remove any arch logs 
from the filesystem except during maintenance outages.  Also, we had *current* 
versions of all the OCFS tools and utilities... fileutils (O_DIRECT).

Oh yeah...is all coming back to me now...we had server hangs during the RMAN 
archive log backup and "deletes" too!  This was more than enough to lead us off 
OCFS for arch logs.

Again, I can not find the actual Oracle supplied reference, but from personal 
experience it would take a lot to get me to use OCFS for arch logs and likely 
my other client would never go for it (again).

From overall OCFS experience I have not doubt (plus personal testing) that with 
the benefit of OCFS comes a large performance penalty (overall, not jsut arch 
log issues)...it doesn't perform as well as RAW...as expressed.

hth

Chris Marquez
Oracle DBA




-----Original Message-----
From: David Sharples [mailto:davidsharples@xxxxxxxxx]
Sent: Mon 10/3/2005 10:21 AM
To: Marquez, Chris
Cc: mueller_m@xxxxxxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: Re: Oracle RAC backup hardware/software recommendation?
 
Can you point me to the docs where it says dont put archivelogs on OCFS -
The OCFS docs says it is quite suitable
 Thanks
 Dave

 On 10/3/05, Marquez, Chris <cmarquez@xxxxxxxxxxxxxxxx> wrote:
>
> We had a totally isolated disk for arch logs (on ocfs). Performance was
> horrible...a huge bottle neck.
> Trust me is was not the hardware (design). As soon as we went to EXT3
> file system the arch log bottle was gone.
>
> BTW, I have seem Oracle docs the recommend *NOT* putting arch logs on
> ocfs.

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