Full vs incremental vs differential

Discussion in 'Acronis True Image Product Line' started by wchull, Dec 21, 2008.

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  1. wchull

    wchull Registered Member

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    I've been a long tome Acronis True Image user but only for full backups whenever I deemed them necessary. Well, I want to make better use of the product and want some advice.

    My system is fairly old but I keep my copy of XP and my software up to date at all times. In doing so, I find that my HD gets fragmented so I end up defragging quite often with PerfectDisk therefore the heart of the question.... If you defrag frequently is there any advantage to doing incremental or diferential backups over doing more frequent full backups? If there is still value in doing an incremental or differental backup which one is better - incremental of differential if you are doing frequent defrags?
     
  2. Aaron Here

    Aaron Here Registered Member

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    Under those conditions I don't see any benefit to incremental/differential backups - certainly not worth the greater probability of a failed recovery that they (especially incrementals!) present ...and for that matter I don't believe there is much, if any, benefit to those frequent defrags either. ;)
     
    Last edited: Dec 21, 2008
  3. wchull

    wchull Registered Member

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    So....From what I gather from reading the doc indicates that incrementals made after defrag would be about as large as the original full backup. The doc really doesn't say anything about the size of a differential backup after a defrag. Would these be about the same size as a full system backup after a defrag? So far it seem that a full system backup is the best route to take and that perhaps I just need to do it more frequently. Any other comments?
     
  4. jehosophat

    jehosophat Registered Member

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    I had a recent incremental after I did a defrag, that ended up taking just as long at the Full backup. I just do full backups now.
     
  5. crofttk

    crofttk Registered Member

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    Just that, defragging aside and theoretically speaking, the differential backup will always be larger than the incremental backup, once you extend the series beyond one incremental or differential backup - that's the nature of a differential, no? The differential includes all incrementals since the last full backup, so the restore involves the full restore plus only one differential restore instead of a series of incremental restores. I'm not sure that incrementals would entail more risk that differentials, just from a purely mathematical standpoint - more baskets for your eggs with incrementals. However, any screwed up backups and restores are awful bad news, whether they involve fulls, incrementals, or differentials and I'm always more comfortable with multiple full backups if I have the magnetic real estate to store them.

    The impact of defragging, of course, more or less cancels out much of the difference between an incremental and differential, in fact probably making the incrementals or differential much larger when you are using a sector based backup - as opposed to an archive bit based backup.

    I'm no doubt guilty of over-defragging only because I run scheduled defrags weekly when I could probably get by with quarterly or semi-annual defrags. Right now, it's a moot point for me since I'm beta testing the next PerfectDisk on multiple machines and don't use a sector based backup.:p
     
  6. Acronis Support

    Acronis Support Acronis Support Staff

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    Hello wchull,

    Thank you for your interesting in Acronis True Image

    The thing is that incremental backup is a type of backup which collects all changes performed on hard drive and compare it with full or last incremental backup. If it is not “as is” then these changes reflect on new lager capacity incremental backup. Note that file defragmentation considers as changes being taken on hard drive. It may also influence on larger capacity incremental/differential backup.

    In order to restore differential backup using Acronis True Image software you should have only one differential backup archive and one full backup archive. In order to restore incremental backup using Acronis True Image software you should have all incremental backup archives and one full backup archive.

    See the link to read more about incremental and differential backups

    Best regards,
    --
    Dmitry Nikolaev
     
  7. jester1966de

    jester1966de Registered Member

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    Having learned just this, I would like to switch from incremental to differential backups. Would it be safe to change this within the already existing task or would it be better to create a new task from scratch (i.e. with initial full backup)?

    Thanks

    jester
     
  8. jester1966de

    jester1966de Registered Member

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    Does no one have an answer to my question? :eek:

    Any hint appreciated!

    Thanks

    jester
     
  9. Aaron Here

    Aaron Here Registered Member

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    Why not just create a new task? - it isn't all that difficult or time-consuming.
     
  10. leoliver

    leoliver Registered Member

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    I do a full back up one week, then a diff back up the next week and then the following week another full back up, etc.
    If my full back up is about 33 GB. , then my diff back ups are about 5 GB. .
     
  11. Acronis Support

    Acronis Support Acronis Support Staff

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    Hello jester1966de,

    Thank you for your interesting in Acronis True Image

    It would be better if you create another task from the scratch with differential backups.

    Best regards,
    --
    Dmitry Nikolaev
     
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