3 different images

Discussion in 'Acronis True Image Product Line' started by geohei, Jul 27, 2008.

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  1. geohei

    geohei Registered Member

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    Hi.

    I generated 3 succeeding images from the ATI bootcd (version 9.5). No system start in between! All 3 were properly validated without error.

    image 1 : 2.074.540.300 bytes
    image 2 : 2.074.543.611 bytes
    image 3 : 2.074.540.721 bytes

    As I said ... they were created one right after the other. How is it possible that their size (hence also content) changed?

    Thanks,
     
    Last edited: Jul 27, 2008
  2. shieber

    shieber Registered Member

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    The size will always be a bit diff each time. It's normal and presents no probs. Could be due to any number fo things, indexing fules, sys restore files, other system files, etc.
     
  3. MrMorse

    MrMorse Registered Member

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    Although there was NO system start between the 3 images?
    I imagine that he starts from rescue-CD and create one image after the other.
    Without a new boot of the PC.

    I cannot believe that there is an indexing or other changes in that partition which was imaged.
    I only can imagine that the target device (where the image is stored) has a different cluster-use of each image. But: the bytes should be the same o_O
     
  4. geohei

    geohei Registered Member

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    I fully agree!

    If the time is different, the bytes should remain identical!

    Yes, there was NO restart of the operating system between the backups.
    Yes, I used the rescue CD.

    Could you please do me the favor and test this with one of your partitions.

    Thanks!
     
  5. Xpilot

    Xpilot Registered Member

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    Perhaps the log entries that are created when images are created in the rescue environment would account for the , to my mind trivial, differences.
    I sugest you check the TI rescue logs while still booted in the recovery enviroment.
    It is not something I have ever been concerned about but have a look anyway.

    Xpilot
     
  6. MrMorse

    MrMorse Registered Member

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    How large is your imaged partition?
    Is it the boot partition?
    (I ask to create a similar environment to test it. And: I test it tomorrow.)



    The logs are stored on the partition that will be backuped?
    No, that I cannot believe.
    But: I am 'learnable' :)


    I test it tomorrow whether there are differences between the images.
     
  7. TheWeaz

    TheWeaz Registered Member

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    "The logs are stored on the partition that will be backuped?
    No, that I cannot believe."

    Why not. While backing up from within Windows all sorts of stuff gets written to the partition being backed up (assuming it's your system partition).
    Also, it can backup everything and THEN write to the log.
     
    Last edited: Jul 27, 2008
  8. Peter2150

    Peter2150 Global Moderator

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    You didn't read what the OP said. He didn't back up from with in wndows, but from the recovery CD.

    Pete
     
  9. Peter2150

    Peter2150 Global Moderator

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    I just tried what OP did with another product. Namely 3 images in a row from the recovery CD

    Results:

    1 19468083KB
    2 19468084KB
    3 19468079KB

    Not sure the significance, but there it is.

    Pete
     
  10. seekforever

    seekforever Registered Member

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    Interesting, like the OP's, the size slightly increases for the second one and then drops for the third one. My guess, and that is all it is, is that it has something to do with the clusters and how things are being counted. In other words, it is a red-herring when trying to figure out what the image program is doing.

    I don't think TI writes anything to the disk, either a log file or anything else and if it did, the size should continually increase not increase then decrease.

    Like I said, my guess for the day.
     
  11. TheWeaz

    TheWeaz Registered Member

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    Yes I did read what was said. You, however, misunderstood what I wrote.
    It was an example of how TI could and does write to the partition being backed up.
    My response was directed to MrMorse.
     
  12. rwt325

    rwt325 Registered Member

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    When restored, are these three images different?. If not, why worry about it?.
     
  13. MrMorse

    MrMorse Registered Member

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    Hi,
    yes, under Windows-Ti it is possible.
    My explanation related to the start with the rescue-cd.

    @all
    The difference of a few bytes (like Peter2150 has) are explicable because Ti adds many checksums to the TIB-file. They may be different from image to image.
    Why? No idea. Perhaps depending on clusters at the target device? Or building checksums with the current date/time?
    The contents of all three images are the same. I'm sure.


    But geohei has once a difference of 3KB ! (see first post).
    That is to much to declare it has to do with clusters.
     
  14. Xpilot

    Xpilot Registered Member

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    In the recovery environment there is a button to view the TI log. This must be one that available to TI and it cannot be the same as the one used by TI when in Windows.
    I have never opened this log and I do not know if it ever contains anything.
    I just tossed it in as a possibility.

    I must go and sharpen my microtome to do some hair splitting :D .

    Xpilot
     
  15. geohei

    geohei Registered Member

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    Hard to check this!
    But basically, you are right!

    Another wild guess from my side ... I used compression maximum when creating the backups. What if an ATI algorithm would include something like a random variable in order to store this should be detectable by creating non-compressed images.

    ... later ...

    Bingo ... 3 backups without compreccion and 3 times identical sizes (3.543.026.894 bytes).

    Hence, it seems to be that the compression adds some kind of random factor ?!
     
  16. shieber

    shieber Registered Member

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    You can run ATI three or more times in succession, one right after the other, backing up a nonsystem disk and the tibs will likely be 3 slightly diff sizes. The more data on the surce disk, the more liekly the diffs. At a minimum, it's a quirk of ATI, but in any event, that's how it works and I've never discovered that it presents any problems of any kind.
     
  17. MrMorse

    MrMorse Registered Member

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    Random? No, I don't think so.
    Acronis will know how the compression works ;) .

    Fact is now you don't worry about this...
     
  18. geohei

    geohei Registered Member

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    When it comes to security and critical software of a server, an admin would like to know how software (which ATI is for me) functions. When I see an unexpected result, I think about it and assume. The random factor in this issue might be desired (for some reason), but it's the only possible explanation I can think of. Probably, only an Acronis guy could confirm it.

    BTW .. I believe that they know what they are doing ;)

    Bye,
     
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