RMAN backup optimization

From: Suresh Chaganti <chaganti.suresh_at_gmail.com>
Date: Wed, 26 Dec 2007 11:57:07 -0600
Message-ID: <1828353c0712260957j4882ce35n6f31ece06408c075@mail.gmail.com>

Hello List

I just got onboard at this client and looking into some performance issues.

HW / SW : 2 Node RAC, 10.2.0.3, 32 CPU, ASM, 32 GB RAM ~ 1.5 TB database

The redolog file size is 2GB and about 20GB redo is generated every hour.

The archive logs are on one of the disk groups of ASM and there is a RMAN job running every 2 hrs backing up archivelogs.

Typically, this job is runnning for 90 minutes to backup about 40GB of archive redo.

There is concern that this RMAN job is hogging too many resources and impacting production application performance. I am still in process of getting familiar with application and environment.

Here is the rman script

 configure backup optimization on;
run {

allocate channel d1 type disk maxpiecesize 1024M maxopenfiles ${FP};
allocate channel d2 type disk maxpiecesize 1024M maxopenfiles ${FP};
allocate channel d3 type disk maxpiecesize 1024M maxopenfiles ${FP};
allocate channel d4 type disk maxpiecesize 1024M maxopenfiles ${FP};
allocate channel d5 type disk maxpiecesize 1024M maxopenfiles ${FP};
allocate channel d6 type disk maxpiecesize 1024M maxopenfiles ${FP};

backup as compressed backupset tag PROD archivelog all format '/u02/RMAN/arc/al_%d_%U.rman';

release channel d1;
release channel d2;
release channel d3;
release channel d4;
release channel d5;
release channel d6;

}
configure backup optimization off;
EOF Is 90 Minutes to backup 40GB of archived redo on this box sound normal?

The backup was running on 2 channels, but was recently modified to 6 channels and users starteed complaining about reduced performance.

One idea came to my mind is investigate if we are better off moving archive destination outside ASM on OCFS or any cluster FS and use OS utilities to compress and backup. Any idea if this will be faster than RMAN backup

Thanks
Suresh

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Received on Wed Dec 26 2007 - 11:57:07 CST