5 Replies Latest reply on Jan 27, 2013 1:43 AM by div

    How to make only 1 file RMAN backup

    A Labadi
      Dear Sir;

      during the last week, we faced many network issues that prevent our RMAN files to be copied completly.
      backup team offer a temporary solution that we have to generate only one backup file to be transfered from source to distination (tape).

      can you please help me how to create only one output file.

      Thanks and best regards
      Ali
        • 1. Re: How to make only 1 file RMAN backup
          Mihael
          can you please help me how to create only one output file.
          set CONTROLFILE AUTOBACKUP off
          allocate only 1 channel
          backup as backupset, not copy
          • 2. Re: How to make only 1 file RMAN backup
            Levi Pereira
            This small test should work.
            RMAN > run{
            Allocate channel t1 <STB Parameters>;
            backup current controlfile tag 'backup_controlfile_test';
            delete noprompt backup tag 'backup_controlfile_test';
            }
            If you want test with more data you can try it.
            RMAN> 
            report schema;
            # Get your filenumber
            backup datafile <filenumber> tag 'backup_datafile_<number>';
            Regards,
            Levi Pereira
            • 3. Re: How to make only 1 file RMAN backup
              EdStevens
              A Labadi wrote:
              Dear Sir;

              during the last week, we faced many network issues that prevent our RMAN files to be copied completly.
              backup team offer a temporary solution that we have to generate only one backup file to be transfered from source to distination (tape).

              can you please help me how to create only one output file.

              Thanks and best regards
              Ali
              I think your backup and network teams are trying to throw their problems "over the wall" to make them a dba responsibility. The ideas suggested to get 'only one backup file' leave you exposed to not having all the pieces you may need for a recovery. What real problem was caused by the failure to get all the backup pieces to tape on schedule? What prevents them from being copied after the "network issues" are resolved? The proposed solution doesn't solve anything, it just moves a problem from one area to another.
              • 4. Re: How to make only 1 file RMAN backup
                Hemant K Chitale
                An RMAN Backup consist of one or more BackupSets. Each BackupSet consists of one or more BackupPieces. The number is controlled by the combination of
                MAXSETSIZE (size of a BackupSet)
                FILESPERSET (number of input datafiles in one BackupSet [default value 64])
                DISKRATIO (OS dependent, number of datafile disks [default value 4])
                MAXPIECESIZE (size of each BackupPiece in a BackupSet)
                Number of Channels used (each Channel creates a separate BackupSet)

                There is an OS specific limit on each PieceSize as well.

                You can "limit" your backup to a single file (BackupPiece) only if it is small enough to fit into the OS specific limit.


                You need to more about the size of the database and the number of datafiles and "play" around with the parameters named above to control the number of BackupPieces created.

                In general, only small databases get limited to one BackupSet consisting of one BackupPiece.


                Hemant K Chitale
                • 5. Re: How to make only 1 file RMAN backup
                  div
                  I agree with EdStevens on this. You are being the victim of a problem that is not really yours.
                  In the event that you still need to have one file, I would suggest, that you zip up all the files from the backup into one file. You will get little to none compression by doing.
                  You should inform your team that this adds time to your SLA on restoring data and they have to live with this.
                  Again this is just a work around of a problem that is really not yours.

                  Div