Backup time not reducing even after DB size went down 300 GB

  • Backup time is almost same and did not reduce after the database size went down by 300 GB.

    What could be the reason?

     

    Thanks in advance.

  • Was the 300GB comprised of data which has since been deleted, or just space?

    If the answer to your question can be found with a brief Google search, please perform the search yourself, rather than expecting one of the SSC members to do it for you.
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  • Deleted data and shrink the data files

  • PJ_SQL wrote:

    Deleted data and shrink the data files

    Understood as to what you've done.  Phil's question is what were the conditions before the shrinks?  For example, if your database had a file size of 600GB but only 300GB contained any data, then shrinking the file will have no effect on the backup times because SQL Server does NOT backup empty/free space.

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
    "Change is inevitable... change for the better is not".
    "Dear Lord... I'm a DBA so please give me patience because, if you give me strength, I'm going to need bail money too!"

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • Database was 500Gb, 200 GB worth data deleted and then shrink files to reclaim space, backup was taking 2 hours before and still taking same time after database reduced to 200 GB

  • PJ_SQL wrote:

    Database was 500Gb, 200 GB worth data deleted and then shrink files to reclaim space, backup was taking 2 hours before and still taking same time after database reduced to 200 GB

    Then I agree.  That's a problem and I've got no idea why that may be unless it's somehow throttled down by something else.  Are you doing it as a single file backup or are you splitting the backup into multiple streams.

    Also, 2 hours to backup even 500GB seems like a pretty long time to me.  I'm backing up at a rate of about 2TB per hour from my prod box.  I have to admit that it's got some pretty hefty connections to it and I'm using backup compression with special settings for buffers, etc, but there shouldn't be that much difference and, most certainly, your backups should not be taking the same time as they were, from what you've described.

     

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
    "Change is inevitable... change for the better is not".
    "Dear Lord... I'm a DBA so please give me patience because, if you give me strength, I'm going to need bail money too!"

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • are you producing striped backup files ?  (  Backup database - working with a striped media set )

    That may also help to reduce the time needed. ( if that is the biggest problem )

    Johan

    Learn to play, play to learn !

    Dont drive faster than your guardian angel can fly ...
    but keeping both feet on the ground wont get you anywhere :w00t:

    - How to post Performance Problems
    - How to post data/code to get the best help[/url]

    - How to prevent a sore throat after hours of presenting ppt

    press F1 for solution, press shift+F1 for urgent solution 😀

    Need a bit of Powershell? How about this

    Who am I ? Sometimes this is me but most of the time this is me

  • Johan Bijnens wrote:

    are you producing striped backup files ?  (  Backup database - working with a striped media set ) That may also help to reduce the time needed. ( if that is the biggest problem )

    Still, that doesn't explain why the backup durations haven't decreased since the deletion of 200GB of a 500GB database.

     

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
    "Change is inevitable... change for the better is not".
    "Dear Lord... I'm a DBA so please give me patience because, if you give me strength, I'm going to need bail money too!"

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • Single File backup

  • Sounds weird. I don't think this is likely just SQL Server. I would start checking to be sure nothing else in infrastructure changed. If you are backing up 200GB now and had 500GB before, it should be faster. I'd also double check that you are measuring things in the same way, before and after. I certainly have been guilty of running one query first, and a different query second.

  • Looking at the backup size, it did not change much just about half the size of what it was before... as we do compress our backups it went from 50 Gb to 25GB and time for backup reduced to just half hour less than what it was before.

  • Double check your target folder itself ( or volume ) has not been enabled for compression !

    SQLServer does weird things when someone enables compression at disk level.

    Johan

    Learn to play, play to learn !

    Dont drive faster than your guardian angel can fly ...
    but keeping both feet on the ground wont get you anywhere :w00t:

    - How to post Performance Problems
    - How to post data/code to get the best help[/url]

    - How to prevent a sore throat after hours of presenting ppt

    press F1 for solution, press shift+F1 for urgent solution 😀

    Need a bit of Powershell? How about this

    Who am I ? Sometimes this is me but most of the time this is me

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