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  1. #1
    Join Date
    Apr 2011
    Posts
    12

    Post Unanswered: Backup of DB is taking too time into tape

    Hi All,
    I have two DB2 instances. Daily we are taking backup to tape manually. But the problem is one DB backup has completed in 23 mins. But another one takes 40 hours to complete the full online backup. May I know the reason why its taking so much time.
    Is there any way to reduce the backup time. Please tell me ASAP.
    Last edited by cooldil; 04-13-11 at 08:42. Reason: note changing

  2. #2
    Join Date
    Jan 2010
    Posts
    335
    Hi,

    which Version of DB2 do you use?
    Which command do you use for Backups?
    What is the size of your databases?

    Cheers
    nvk

  3. #3
    Join Date
    Apr 2011
    Posts
    12

    Backup of DB is taking too time into tape

    Thanks for your reply.

    We are using db2 v9.1.

    The command to take the backup is

    db2 backup db QAS onine to dev/rmt0 parallesim 4 include logs &

    And my size of the db is 110 GB.

    For PRD db it take 22 mins. But this QAS db it has taken 40 hrs.

    Could you please help me on this.
    Last edited by cooldil; 04-13-11 at 10:45. Reason: s

  4. #4
    Join Date
    Jan 2010
    Posts
    335
    The Database has the same size in prd and qas?

    You can check the progess of a backup with
    db2 list utilities
    So you can see the transfer-rate for both databases.

    Things you may want to check:
    - Load on the System during backup
    - Where do you store your archive-logs? And how many logs you have to include in the backup? Maybe try backup with "exclude logs".
    - Differences in DB or DBM Parameters?

  5. #5
    Join Date
    Aug 2008
    Location
    Toronto, Canada
    Posts
    2,367
    Also, check if there is any lock contention during online backup (ie. it can conflict with the load utility).

  6. #6
    Join Date
    Apr 2011
    Posts
    12

    Backup of DB is taking too time into tape

    Hi,

    Thanks for ur reply................

    I checked in list utilities... It takes 1/2 an hour to completed 1% of the backup.

    The system ideal state is 80% during the backup.

    Only I have included the logs which I required to restore the db.(online backup).

    There will be a difference in both DBM cfg parameters. CPU speeed

    CPU speed (millisec/instruction) (CPUSPEED) = 4.447908e-07 -- PRD

    CPU speed (millisec/instruction) (CPUSPEED) = 2.834065e-07 --QAS

    Please provide me a sloution.

  7. #7
    Join Date
    Apr 2011
    Posts
    12

    Post Backup of DB is taking too time into tape

    Hi

    The DB size is same in both databases...........

    Cheers,
    Dil

  8. #8
    Join Date
    Jan 2009
    Location
    Zoetermeer, Holland
    Posts
    746
    Quote Originally Posted by nvk@vhv View Post
    Maybe try backup with "exclude logs".
    Bad advice! An online backupimage without the logs is useless. Maybe now you've still got the logs, but after a longer period of time you will need for whatever reason to restore and you'll be very happy with the included logs to create a working database after the restore.

    Got some space left on disk? Make a backup on disk and see how long that takes. Then you know if the tape-unit is the bottleneck or not.

  9. #9
    Join Date
    Apr 2011
    Posts
    12

    Backup of DB is taking too time into tape

    Hi All,

    is there any advice to reduce the time of the backup of the db.

    Reg,
    Dil.

  10. #10
    Join Date
    Aug 2008
    Location
    Toronto, Canada
    Posts
    2,367
    Do you see any lock contention during QAS backup?
    How long does it take to backup QAS to /dev/null?

    General guidelines for improving backup perf:
    IBM DB2 9.7 for Linux, UNIX and Windows Information Center

    Compare the number and size of bufferpools between QAS and PRD dbs

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