Managing Differential Backups

Discussion in 'Acronis True Image Product Line' started by mwilg, Apr 30, 2006.

Thread Status:
Not open for further replies.
  1. mwilg

    mwilg Registered Member

    Joined:
    Apr 2, 2006
    Posts:
    23
    Location:
    Tulsa, OK
    Quick/easy question...hopefully(!)
    I have set it up to where it is automatically running a diff backup twice a week, but what I didn't expect was ea diff b/u is a new file. I expected it to just create/overwrite one diff file; ie. you have the original b/u file and just one other diff b/u file that is modified or rewritten ea time. Anyways, can I not just delete any older (than the most recent) diff b/u files and just keep the most recent? Otherwise, I'm bound to eventually use up all the space.

    BTW, Chustman, I have another literary pet peeve I could add to your tag line - the plural possessive is 'their' not 'there' :)
     
  2. TheWeaz

    TheWeaz Registered Member

    Joined:
    Jul 9, 2005
    Posts:
    1,562
    To use a DIFF to restore, you only need the FULL and the DIFF that was created on the date from which you wish to restore. You do not need the DIFFs in between. There is, I believe, a problem TI currently has with verifying DIFF images – the verify requires the FULL and all the DIFFs between the FULL and DIFF you wish to verify.
    How often do you rerun the FULL backup? Once you do that, the DIFFs will start to overwrite themselves.
     
  3. mwilg

    mwilg Registered Member

    Joined:
    Apr 2, 2006
    Posts:
    23
    Location:
    Tulsa, OK
    I actually haven't rerun the full b/u since the 1st time. So I should rerun it & overwrite the previous full b/u?
     
  4. Menorcaman

    Menorcaman Retired Moderator

    Joined:
    Aug 19, 2004
    Posts:
    4,661
    Location:
    Menorca (Balearic Islands) Spain
    Hello mwilg,

    It wouldn't be a bad idea because, depending on how many changes have taken place to your HD in the meantime, your new differential images will likely be smaller. Note, however, that from the moment you overwrite the previous full backup all exisisting differential images will become orphaned/redundant.

    Regards
     
  5. Howard Kaikow

    Howard Kaikow Registered Member

    Joined:
    Apr 10, 2005
    Posts:
    2,802
    You also would have to delete the differential backups that were created before the new full backup.
     
  6. mwilg

    mwilg Registered Member

    Joined:
    Apr 2, 2006
    Posts:
    23
    Location:
    Tulsa, OK
    Ok, tks. We'll see what happens after that with any new crop of diff files.
     
  7. Menorcaman

    Menorcaman Retired Moderator

    Joined:
    Aug 19, 2004
    Posts:
    4,661
    Location:
    Menorca (Balearic Islands) Spain
    Not strictly necessary. Provided mwilg uses the same name for the new full backup as the old, then each new differential image will sequencially overwrite the previous one.
     
  8. mwilg

    mwilg Registered Member

    Joined:
    Apr 2, 2006
    Posts:
    23
    Location:
    Tulsa, OK
    ...which I will do, so sounds like the simplest thing is to just run a full b/u ea month and that will restart the process.
     
  9. Howard Kaikow

    Howard Kaikow Registered Member

    Joined:
    Apr 10, 2005
    Posts:
    2,802

    If you are going to go 1 month between full backups, then I would recommend using incremental, rather than differential, backups.

    1. You will use much less disk space than if you saved multiple differential backups.
    2. If you save only the last differential backup and you lose/corrupt that file, then you lose ALL the changes since the full backup.
    3. Incremental backups give more recovery points from to choose, using much less disk space.
     
  10. mwilg

    mwilg Registered Member

    Joined:
    Apr 2, 2006
    Posts:
    23
    Location:
    Tulsa, OK
    The only thing I have against inc's is trying to find a particular folder or file. At least with diff's you only have two places to look for the latest version. I haven't gotten around to using the plug/unplug image function yet, and maybe that 'masks' all the different inc files by creating them as one virtual drive, which'd be nice.
     
  11. TheWeaz

    TheWeaz Registered Member

    Joined:
    Jul 9, 2005
    Posts:
    1,562
    “At least with diff's you only have two places to look for the latest version”

    If you mount the latest INC, wouldn’t that ensure the latest version of any file?
     
  12. Howard Kaikow

    Howard Kaikow Registered Member

    Joined:
    Apr 10, 2005
    Posts:
    2,802
    FYI, if you want to find the latest file, you only need to look at the latest incremental, just as with a differential.

    However, incrementals do allow you to get earlier versions.

    And, the program I posted yesterday will allow you to see what is different in each incremental. See http://www.standards.com/index.html?CompareDrives.
     
  13. mwilg

    mwilg Registered Member

    Joined:
    Apr 2, 2006
    Posts:
    23
    Location:
    Tulsa, OK
    Hmm, interesting info from Howard there, tks. My understanding of inc's was that the latest verson of a file could be anywhere depending on when it was last updated and how many inc files there are. I'll take a look at that linked program though, that looks promising.
     
  14. Howard Kaikow

    Howard Kaikow Registered Member

    Joined:
    Apr 10, 2005
    Posts:
    2,802
    Yes, with incrementals, the file can be anywhere, but when you select ANY incremental, you get access to the LATEST files in that, AND earlier, incrementals.
     
  15. TheWeaz

    TheWeaz Registered Member

    Joined:
    Jul 9, 2005
    Posts:
    1,562
    To add to Howard's reply -

    When you look at any DIFF, you are really looking at 2 files – the FULL and that particular DIFF. When looking at an INC, you are looking at that INC, the FULL and all INCs in between.
     
  16. mwilg

    mwilg Registered Member

    Joined:
    Apr 2, 2006
    Posts:
    23
    Location:
    Tulsa, OK
    Ah, well tks for the info. I didn't realise it was that easy; I thought one would have to manually search through all the inc's. Good education for me :cool:
     
Thread Status:
Not open for further replies.