Why did I do an incemental backup?

Discussion in 'Acronis True Image Product Line' started by mtroxel, Nov 6, 2006.

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  1. mtroxel

    mtroxel Registered Member

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    I backed up an image of my drive a few months ago, right after I got Acronis 9. I split into three DVD sized files totalling 11.7 Gigs. After I repartitioned, installed Vista beta, then decided to go back I restored from that image. Worked great!

    Now I go to update that, so I did an incemental backup hoping that means:

    1. The additional image store would be very small, just the new data.
    2. I could later choose between restoring the original image, or restoring the original plus the new incremental data.

    What I got was an additional 3 DVD sized files totalling 12.5 Gigs. Now I have 24 Gigs of files that would just be 12.5 Gigs if I did a full backup again. And, when I start a restore, it looks like I can only restore the entire 6 files...meaning I can't just go back to the original backup image.

    So, why did I do an imcremental backup? Seems like I should just take a full backup image. It will take the same amount of space, and I'll have more options. What am I missing?
     
  2. Tabvla

    Tabvla Registered Member

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    The reason why your "incremental" backup is so big is because you repartitioned the disk between the Full and Incremental backups. This has changed the file locations resulting in the large "incremental".

    Exactly the same thing will happen if you defragment the disk between a Full backup and an Incremental backup.

    Providing the structure does not change between Full and Incremental, the incremental will, normally, be considerably smaller than the Full.
     
  3. mtroxel

    mtroxel Registered Member

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    Shoot, that makes sense. That's quite a limitation...espc when you throw in the "do not defragment" thing. Guess I'll just do full backups and save them to DVD.

    If I wanted to restore just my original 11.7 backup image without the incremental changes, could I do that?
     
  4. TheWeaz

    TheWeaz Registered Member

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    "If I wanted to restore just my original 11.7 backup image without the incremental changes, could I do that?"

    Yes, that should not be a problem.
     
  5. Tabvla

    Tabvla Registered Member

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    Not really.... when you repartition or defrag a drive you change (potentially) all the file associations. ATI correctly sees this as a change to the file status and correctly backs-up the entire file again.

    Therefore the need to create a new Full backup after a repartition or a defrag.

    For the most part this is not a problem because under normal circumstances you would only repartition or defrag very occasionally - by which time it is probably a good idea to create a new Full backup.
     
  6. TheWeaz

    TheWeaz Registered Member

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    Just to be clear, an image backup (not a Files/Folders backup) backs up “in-use sectors”.
    Whether a file, or its association, has changed does not come into play. TI could not care less. If a file, left unchanged, has been moved, TI will include that move in an INC image. It's the changing sectors it cares about.
     
  7. Tabvla

    Tabvla Registered Member

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    Hi TheWeaz

    Thanks, your wording does clarify what I meant.

    In this context the use of "file associations" is perhaps not the best.

    Tabvla
    :)
     
  8. bVolk

    bVolk Registered Member

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    mtroxel,

    If you'll be storing your image files on DVDs you should indeed stay with full images only, even if you do not defragment or repartition. I never tried to restore from an incremental set stored on DVDs, but I expect it would call for a lot of disk shuffling.
     
  9. mtroxel

    mtroxel Registered Member

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    I'm not sure why I chop it up into DVD size chunks. The two times I've restored I've always put the files on a portable hard drive and restored from that.
     
  10. TonyTech

    TonyTech Registered Member

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    Since Windows will begin to run slowly without regular defragmenting and defragmenting increases incremental image sizes, I've pretty much abandoned doing incremental images and also jetisoned the secure zone. I have one initial image and a latest image that I replace regularly. (Another reason not to use secure zone is because you can't manage or wipe images that you create there and that is a potential security issue).
     
  11. mtroxel

    mtroxel Registered Member

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    That's what I'm concluding. I'd like to go back to my earliest image....then keep making more current full backup images.
     
  12. foghorne

    foghorne Registered Member

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    Logically true. Although this does not mean that a full image is necessarily quicker to produce or results in a smaller file than an incremental, even with defragmentation.

    F.
     
  13. Tabvla

    Tabvla Registered Member

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    Just to clarify.....

    Windows performance will degrade noticeably if the pagefile becomes fragmented into several fragments because Windows will be thrashing the disk while it pages content between RAM and virtual memory. In practice if the pagefile is fragmented up to about 4 fragments it does not seem to make a noticeable difference, more than 8 fragments is noticeable.

    Generally a user will not notice a performance degradation until overall file fragmentation reaches about 10%. On a home computer it would typically take many months to reach 10%. Even in a busy Small Business environment it is usually only necessary to defrag every 3 months.

    In view of the above, performing incremental/differential backups is still the preferred method due to the relative speed and small footprint, with occasional full backups after a defrag.
     
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