Differential Backups - What to keep

Discussion in 'Paragon Drive Backup Product Line' started by lordriver, Jan 4, 2011.

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  1. lordriver

    lordriver Registered Member

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    Hi all.

    I guess this is a simple question. I have an external hard drive that I have partitioned.

    I have made a full backup of my internal drive onto one partition. On the second partition, I have made a differential.

    The full backup is about 150g, the differential is about 4g.

    Firstly, will the fact that the differential and original backups are on different partitions screw things up?

    Secondly, when I make another differential, do I need to keep the first differential? If I have 20 differentials (daily), what do I need to keep?

    Thirdly, at what point do you suggest that I create a new master backup and wipe out everything else?

    Thanks!
     
  2. Cudni

    Cudni Global Moderator

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    You need to keep all differential backups (if any only the last one in sequence can be removed). Were the differential backups subsequently moved after the full backup was created? I would suspect software needs to have them all in one place on restore.
     
  3. lordriver

    lordriver Registered Member

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    No, the partitions were made before I created the backups. First I created the main archive on one partition, and then I created the differential on another.

    The software didnt complain. Do you think this will be an issue?

    So, what you are saying is that the differential backups are like a chain, and they are ALL needed to restore? The previous differentials are used when creating a new differential?

    Thanks!
     
  4. pegas

    pegas Registered Member

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    I don't think so. As I understand you only need to keep the full base backup. Every differential backup does do it to the base backup. However Paragon staff can shed more light.
     
  5. Cudni

    Cudni Global Moderator

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  6. lordriver

    lordriver Registered Member

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    This is what the manual defines a differential backup as:

    "to a sector image to only archive changes since the last full sector-based image, thus considerably saving the backup storage space. To restore this kind of backup you will require a full image and one of its differentials."​

    This leads me to believe that I can delete any differentials that I want, and only keep, say, the last 5.

    However, the literature goes on to state the following, about FILE BACKUPS:

    "An incremental archive only contains data changed since the time of creating a full or incremental file-based archive. It is smaller and takes less time to create, but you will require the initial full image and all of its increments to restore the latest point of this kind of backup."​

    This leads me to believe that all the differentials are in fact needed.

    So, a sector backup needs only one differential (if any at all), and the full archive. A file backup needs all differentials.

    I did a disk archive - which is all my partitions, and all my files, everything.

    Was this a sector by sector backup, or a file backup? My archive has the little hard drive logo next to it.

    Anyone care to shed more light on this confusing (to me) subject?
     
  7. lordriver

    lordriver Registered Member

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    Bump. Any staff know the answer here?

    At least to the question of having the main and differential backups on two different partitions?
     
  8. lordriver

    lordriver Registered Member

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    Should be some simple questions for the developers. Any support here?
     
  9. pegas

    pegas Registered Member

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    I am also curious to learn it because I still tend to disagree with Cudni's post as regards differential backups (images). What I have learned only Cyclic backups you need to keep all them because of keeping backup strings, it is like an incremental backup. Moreover I have studied my differential backups and have found that every differential backup of my disk includes all files from the whole disk including the hidden partitions.
     
    Last edited: Jan 11, 2011
  10. Mech_An

    Mech_An Registered Member

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    You can delete old Differential backups any time you want. They are fully independent one from another. The only thing which is mandatory for successful restore from differentials is Full base backup.

    It doesn't matter where diff and full are saved. Even if full backup location was changed after Diff creation you will be prompted to point the full backup location and restore will continue.
     
  11. pegas

    pegas Registered Member

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    Thx Mech_An for clarification :thumb: I thought so.
     
  12. lordriver

    lordriver Registered Member

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    That's great on the location. Thanks!

    So, just to clarify - I have a daily differential backup running every night. They all store in the same folder - I can delete the older ones and the newer ones contain all the information I need?
     
  13. Mech_An

    Mech_An Registered Member

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    @lordriver

    Yes. Older diff backups could be deleted.
    Each new diff contains all changed sectors since Full base backup.
     
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