Results 1 to 8 of 8
  1. #1
    Join Date
    Jun 2009
    Posts
    272

    Unanswered: Reducing backup time

    Currently our database is running DB2 V9.5 FP3 on AIX

    We have four user tablespaces and they are SMS. All those four tablespaces have regular, index and LOB data in it. Backing up this database is taking a lot of time. 300 GB database is taking 8 hours of time. Backup is being taken with compress yes option.

    Is there any way to reduce the backup time ?
    Does converting SMS tablespaces to DMS decrease the backup time ?
    Will seperating Regular, Index and LOB data in to seperate tablespaces reduce the backup times?

    Any suggestions would be greatly appreciated.

  2. #2
    Join Date
    Apr 2012
    Posts
    1,034
    Provided Answers: 18
    Are you backing up to disk or to tape?
    What is the backup tool you are using?
    If you are backing up to disk, what is the backup command-line you are using?
    If you are backing up to disk, are the target file-system(s) sharing the same physical disks as the SMS containers?

  3. #3
    Join Date
    Jun 2003
    Location
    Toronto, Canada
    Posts
    5,516
    Provided Answers: 1
    Quote Originally Posted by blazer789 View Post
    Backing up this database is taking a lot of time. 300 GB database is taking 8 hours of time. Backup is being taken with compress yes option.
    If you are more concerned with the backup time than the space utilization, which I believe is the case, the first thing I'd do is turn off compression.

  4. #4
    Join Date
    May 2003
    Location
    USA
    Posts
    5,737
    1. Write to multiple backup files at once:
      backup db sample to file1, file2, file3, file4 ....
      It is best if each file is on a separate mount point if possible.
    2. Use multiple containers for each large tablespace.
    3. Let DB2 choose the backup options (parallelism, buffers, etc)
    4. Significantly increase UTIL_HEAP_SZ in db config (at least 10 times bigger than you have now).
    5. As mentioned, don't compress, but I would try the above first if compression is important.
    M. A. Feldman
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows
    IBM Certified DBA on DB2 for z/OS and OS/390

  5. #5
    Join Date
    Jun 2009
    Posts
    272
    Thanks everyone for your Answers.
    @db2mor:


    Are you backing up to disk or to tape? - Disk
    What is the backup tool you are using? - Just the regular db2 backup command
    If you are backing up to disk, what is the backup command-line you are using? - backup db dbname online compress yes to /db2backups
    If you are backing up to disk, are the target file-system(s) sharing the same physical disks as the SMS containers? - No

  6. #6
    Join Date
    Nov 2011
    Posts
    334
    external storage or local storage you used to back db?
    10m/s is a bit slow for a normal backup。
    Last edited by fengsun2; 07-10-12 at 03:19.

  7. #7
    Join Date
    Jun 2009
    Posts
    272
    @fengsun: Local storage

  8. #8
    Join Date
    Aug 2001
    Location
    UK
    Posts
    4,650
    Also, check the cpu and disk utilization at the time of backup.

    In certain patch levels of AIX, psmd is known to cause high CPU utilization.

    If I happen to find the APAR id, I will post the info
    Visit the new-look IDUG Website , register to gain access to the excellent content.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •