8 Replies Latest reply on Mar 25, 2013 1:06 PM by azodpe

    system performance duiring RMAN backup.

    azodpe
      Hi,

      We do RMAN everynight. After R1213 upgraded the data is growing at higher speed. At present we have 410 GB database.

      It takes around 4 hrs for RMAN backup. Is that normal? WE are using 4 channels.

      The main issue is the system performance goes down when backup is running

      Where can I look to resolve the issue.

      We are on 11.2.0.2

      Thanks n Advance,
        • 1. Re: system performance duiring RMAN backup.
          mseberg
          Hello

          Here's my times from last night on a 100GB database, Full backup to Disk - Very fast SAN ( new ) ( My version 11.2.0.3 )

          Start Time 03/21/2013:08:01:26

          End Time 03/21/2013:09:03:51

          So your times look OK compared to mine.

          For system performance you could set the "RATE Channel Parameter" in RMAN to control this :

          http://docs.oracle.com/cd/E11882_01/backup.112/e10642/rcmtunin.htm#BABDCEHG

          It would mean a longer backup time, but performance would not suffer as much.

          Best Regards

          mseberg
          1 person found this helpful
          • 2. Re: system performance duiring RMAN backup.
            TSharma-Oracle
            It takes around 4 hrs for RMAN backup. Is that normal? WE are using 4 channels.
            Depends on the power of your machine. I will object iif my RMAN backup will take this much time. Our 4.5 terabytes takes 3.5 hours. So it really depends upon the power of the machine.
            The main issue is the system performance goes down when backup is running
            It could be b cause of I/O's, CPU , tape drive throughput etc.
            Where can I look to resolve the issue.
            Everything is on Metalink:

            RMAN Performance Troubleshooting [ID 1326686.1]
            RMAN Performance Tuning Using Buffer Memory Parameters [ID 1072545.1]
            RMAN Tips: Test Plan to identify correct number of channels for RMAN compressed backups optimal performance [ID 1435723.1]
            Known RMAN Performance Problems [ID 247611.1]
            1 person found this helpful
            • 3. Re: system performance duiring RMAN backup.
              Levi Pereira
              Are you using MML or DISK ?

              What you mean perfomance goes down? What happen (e.g Disk busy/ CPU 100%, Query Slow)?
              • 4. Re: system performance duiring RMAN backup.
                J19
                Hi

                Are you using Grid control then you can check the backup report details from grid. Connect the database from Grid and click- Availability - Backup Reports. Then you can see the below output.

                As per the given report previous backups were run around 9-10 hrs shown as given below but the last two backups taken more time Because output rate is only 23-24 mb per second As shown below due to the data transfer rate marked in bold.


                Backup Name           Status          Start Time               Time Taken     Type          Output Devices     Input Size     Output Size     Output Rate (Per Sec)
                                                        
                2011-02-04T22:00:12     COMPLETED     Feb 4, 2011 10:01:50 PM EST     *13:26:14*     DB INCR          SBT_TAPE     1.22T          *1.14T*          *24.67M*
                2011-01-28T22:00:14     COMPLETED     Jan 28, 2011 10:01:54 PM EST     *14:21:19*     DB INCR          SBT_TAPE     1.22T          *1.14T*          *23.09M*
                2011-01-21T22:00:11     COMPLETED     Jan 21, 2011 10:01:39 PM EST     *9:21:09*          DB INCR          SBT_TAPE     1.22T          *1.14T*          *35.43M*
                2011-01-14T22:00:12     COMPLETED     Jan 14, 2011 10:02:37 PM EST     *9:38:55*          DB INCR          SBT_TAPE     1.22T          *1.14T*          *34.33M*
                2011-01-07T22:00:09     COMPLETED     Jan 7, 2011 10:01:38 PM EST     *9:50:25*          DB INCR          SBT_TAPE     1.22T          *1.14T*          *33.66M*


                you should be compare previous backup output rate. If it is low then you need to check which backup device(ex: Tivoli) are you using your database. if you are using any device type or backup server and then you need to check the device type or backup server health checkup. And also you need to check any jobs are scheduled other than backup that particular time.

                Note: Let me know which backup type are you using.

                Regards,
                Jey
                1 person found this helpful
                • 5. Re: system performance duiring RMAN backup.
                  J19
                  Hi

                  If you are not using Grid control then you can use following.


                  SQL> desc rc_backup_set_details;
                  Name Null? Type
                  ----------------------------------------- -------- ---------------
                  SESSION_KEY NUMBER
                  SESSION_RECID NUMBER
                  SESSION_STAMP NUMBER
                  DB_KEY NOT NULL NUMBER
                  DB_NAME NOT NULL VARCHAR2(8)
                  BS_KEY NOT NULL NUMBER
                  RECID NUMBER
                  STAMP NUMBER
                  SET_STAMP NOT NULL NUMBER
                  SET_COUNT NOT NULL NUMBER
                  BACKUP_TYPE VARCHAR2(1)
                  CONTROLFILE_INCLUDED VARCHAR2(7)
                  INCREMENTAL_LEVEL NUMBER
                  PIECES NOT NULL NUMBER
                  START_TIME DATE
                  COMPLETION_TIME DATE
                  ELAPSED_SECONDS NUMBER
                  BLOCK_SIZE NUMBER
                  KEEP VARCHAR2(3)
                  KEEP_UNTIL DATE
                  KEEP_OPTIONS VARCHAR2(11)
                  DEVICE_TYPE VARCHAR2(255)
                  COMPRESSED VARCHAR2(3)
                  NUM_COPIES NUMBER
                  OUTPUT_BYTES NUMBER
                  ORIGINAL_INPUT_BYTES NUMBER
                  COMPRESSION_RATIO NUMBER
                  STATUS CHAR(1)
                  ORIGINAL_INPRATE_BYTES NUMBER
                  OUTPUT_RATE_BYTES NUMBER
                  ORIGINAL_INPUT_BYTES_DISPLAY VARCHAR2(4000)
                  OUTPUT_BYTES_DISPLAY VARCHAR2(4000)
                  ORIGINAL_INPRATE_BYTES_DISPLAY VARCHAR2(4000)
                  OUTPUT_RATE_BYTES_DISPLAY VARCHAR2(4000)
                  TIME_TAKEN_DISPLAY VARCHAR2(4000)
                  ENCRYPTED VARCHAR2(3)
                  BACKED_BY_OSB VARCHAR2(3)


                  Are you using incremental backup?
                  if you are using the INCR backup..... then are you enbled block change tracking?

                  Regards,
                  Jey
                  • 6. Re: system performance duiring RMAN backup.
                    azodpe
                    Thanks for your response.
                    I will look into the link.
                    • 7. Re: system performance duiring RMAN backup.
                      azodpe
                      Thanks. I alreday have gone through some notes.
                      I will definitely look into others.
                      • 8. Re: system performance duiring RMAN backup.
                        azodpe
                        No we are not using grid control