RE: Oracle RAC backup hardware/software recommendation?

  • From: "Marquez, Chris" <cmarquez@xxxxxxxxxxxxxxxx>
  • To: "Hallas, John, Tech Dev" <John.Hallas@xxxxxxxxxxxxxxxxx>, <mueller_m@xxxxxxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 29 Sep 2005 10:29:09 -0400

>> We do not have to mess around with the MML config
>> we just ensure that the NSR_CLIENT is set correctly
>> and privileges are correct within Networker 

Well, I would call that the "config". ;o)

But yes this is exactly what I mean.
Its hit the DBA smack in the face when one tries to 
        RMAN>restore archive log all;
in a RAC environment where the "local" arch logs are backed up independently on 
each server (instance) in the RMAN backup session/script.  The logs belong to 
one database, but two MML clients.
The RMAN-MML restore session will blow up because it is restoring the logs for 
one client only at a time, but the RMAN command was for ALL logs (from any 
instance...incompatible).
I would set up each TDPO client database server to be able to "spoof" the other 
RAC server at anytime.
That meant duplicate config files on each client RAC server.  So at anytime I 
could restore (RMAN) backup from node A to node A, and backup from node B to 
node A...thus getting all of my arch logs file in a failure.

You don't want to  *learn* this in the heat of battle, but not is not intuitive 
during the set up.
Again, #1 Test, Test, Test complete and total loss database restores.  Then and 
only them "missed" issue become obvious.

Thus a strong argument can be made for cluster filesystem for arch logs (Which 
ocfs does not support/recommend).


PS
>>We don't use RAC (well I don't!!)
We might stop using RAC...but that is a whole other thread, for another day. :o|


Chris Marquez
Oracle DBA






-----Original Message-----
From: Hallas, John, Tech Dev [mailto:John.Hallas@xxxxxxxxxxxxxxxxx]
Sent: Thu 9/29/2005 9:53 AM
To: Marquez, Chris; mueller_m@xxxxxxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: RE: Oracle RAC backup hardware/software recommendation?
 
Well thought out and interesting response Chris. 

I am interested in your point 3. 

We don't use RAC (well I don't!!) but do have occasions when we restore
archived log files from the MML/Tape Robot when they were backed up on
Client A and the database is now on Client B. (cluster and the databse
has failed over to the alternate node). We do not have to mess around
with the MML config, we just ensure that the NSR_CLIENT is set correctly
and privileges are correct within Networker (or whichever MML you will
be using)

Have I misunderstood your point or is it RAC specific?

John

-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Marquez, Chris
Sent: 29 September 2005 14:09
To: mueller_m@xxxxxxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: RE: Oracle RAC backup hardware/software recommendation?

...

3.) On the same note as #2 above learn now that Oracle-RMAN sees a
"backup" as a whole...a single logical unit, while *ANY* MML sees
individual pieces of data from a client (machine).  This becomes
critical when you are trying to restore *ALL* (local) arch log files at
one time from two DIFFERENT clients...or you are trying to restore all
the datafiles backed up from RAC-node A to RAC-node B.  These are the
same database and RMAN backup, but different clients as far as the MML
is concerned.  Server "spoofing" with MML config files is a must "know"
with RAC and MML.

hth

Chris Marquez
Oracle DBA




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