Backup Compression

  • Comments posted to this topic are about the item Backup Compression

    Thanks

  • Nice question

    If everything seems to be going well, you have obviously overlooked something.

    Ron

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  • That's two wrong in a row for me 🙁

  • First attempt this year, and was lucky 🙂

    Good question ... thanks.

    Kwex.

  • Thanks for the easy and straightforward question. Sometimes not having to think hard first thing in the morning is great.

    And then I started thinking ... but WHY can't they co-exist? Is it a design choice, or is there a physical limitation that prevents this from being implementable?

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  • Went with my gut and got it right. Thanks for the question.

    http://brittcluff.blogspot.com/

  • Good question, thanks.

    M&M

  • Hi,

    More information about the restriction can be found at the below link;

    http://support.microsoft.com/kb/2297053

  • Thomas Abraham (1/5/2012)


    Thanks for the easy and straightforward question. Sometimes not having to think hard first thing in the morning is great.

    And then I started thinking ... but WHY can't they co-exist? Is it a design choice, or is there a physical limitation that prevents this from being implementable?

    Hi ,

    You can find more information at the below link;

    http://support.microsoft.com/kb/2297053

  • arun1_m1 (1/5/2012)


    Thomas Abraham (1/5/2012)


    Thanks for the easy and straightforward question. Sometimes not having to think hard first thing in the morning is great.

    And then I started thinking ... but WHY can't they co-exist? Is it a design choice, or is there a physical limitation that prevents this from being implementable?

    Hi ,

    You can find more information at the below link;

    http://support.microsoft.com/kb/2297053

    Thanks for the link. However, I don't think it explains the underlying reason that this must be the case. It explains the results of attempting to add a backup in the different permutations, but it doesn't explain WHY that MUST be the way it works. What is there about mixing a compressed and uncompressed backup in the same media set that is either impossible or undesirable to implement?

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  • Exactly. I agree that this limitation really makes no sense. There's no reason why two backups can't go to the same file, one compressed, one not compressed, and that link merely explains how and not why.

  • Gut said one way, but never tried it the way the third option said. Went with gut and got it right.

    Jason...AKA CirqueDeSQLeil
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  • I happened to have been researching this just a few months ago since we have started to go with compressed backups for the servers that support it. Nice question.

  • Thomas Abraham (1/5/2012)


    arun1_m1 (1/5/2012)


    Thomas Abraham (1/5/2012)


    Thanks for the easy and straightforward question. Sometimes not having to think hard first thing in the morning is great.

    And then I started thinking ... but WHY can't they co-exist? Is it a design choice, or is there a physical limitation that prevents this from being implementable?

    Hi ,

    You can find more information at the below link;

    http://support.microsoft.com/kb/2297053

    Thanks for the link. However, I don't think it explains the underlying reason that this must be the case. ...

    But it does answer at least part of your question. As the article states, the compression setting is stored in (and hence read from) the header of the media set. That, at least, was clearly a design choice on Microsoft's part. Why they made that choice is anyone's guess.

    My guess is that it was inherited from tape systems, as the compression option for tape was historically implemented in firmware because back in the day general purpose CPUs weren't fast enough or were too busy doing other tasks to compress the data as well.

  • That brings up an interesting question -- how many DBAs have their backups go straight to tape? In my professional career I have never had a backup infrastructure where the SQL Server was backing up straight to tape; we always do backup to disk first and then a subsequent backup to tape. That way the backups are locally available for other purposes. Isn't the idea of setting up a backup process to primarily center around tape options a little bit archaic in itself? I mean, you want to keep the tape options in the system, but I would think that file-based options would be more in line with the typical default structures. And to use a "media set" to drive backup issues assumes that you are using tape, IMO.

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