RE: rman allocate channel suddenly taking forever

From: John Hallas <john.hallas_at_bjss.co.uk>
Date: Wed, 19 Sep 2007 11:46:32 +0100
Message-ID: <E02CB9B2777CF8459C86C49B48C48EC6024B5FFB@exchange.bjss.co.uk>

At one site I worked at they had several concurrent catalogs but generated new ones and switched the backups to use the new catalog and then removed the old one after a few weeks when the backups past their retention times.  

If the catalog was not switched then had massive enqueue problems when querying the catalog  

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From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Robert Freeman
Sent: 19 September 2007 03:34
To: gcunningham_at_proteus-technologies.com; oracle-l_at_freelists.org Subject: RE: rman allocate channel suddenly taking forever  

We are having some major performance problems with our recovery catalogs these days!!

Contact Oracle and open an SR, there are several bugs open with catalog performance and degrading performance.

RF  

Robert G. Freeman
Oracle Consultant/DBA/Author
Principal Engineer/Team Manager
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from Osborne/McGraw Hill (Oracle Press)
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BLOG: http://robertgfreeman.blogspot.com/ Sig V1.2

	-----Original Message-----
	From: oracle-l-bounce_at_freelists.org


[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of Gerald Cunningham

	Sent: Tuesday, September 18, 2007 12:50 PM
	To: oracle-l_at_freelists.org
	Subject: rman allocate channel suddenly taking forever

	Hi all,

	 

	We run an rman level 0 backup of a Dataguard physical target

database, twice a week, to disk. The first thing the job does is allocate 10 disk channels. This part of the job (the allocate commands) usually takes 40 minutes to a little over an hour. For the last 3 runs of this backup job, however, the allocate is taking over 9 hours.          

        I should note that this is a very large database with 10's of thousands of data files. This is Oracle 9.2.0.7 64-bit on Solaris.          

        Any suggestions as to what we might look at? What exactly happens internally during the allocate channel command? My rman catalog db is generating 3.1 Gb or archive logs during the 9 hours that the allocate channel commands are running.          

        Thanks for any help or pointers... we've searched Metalink but came up with nothing.                    

        Jerry

BJSS Limited, 1st Floor Coronet House, Queen Street, Leeds LS1 2TW. Registered in England with company number 2777575. http://www.bjss.co.uk

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Received on Wed Sep 19 2007 - 05:46:32 CDT