Imaging Zero-ized

Discussion in 'backup, imaging & disk mgmt' started by nozzle, Mar 4, 2014.

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  1. nozzle

    nozzle Registered Member

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    I wiped my freespace with zeros and made an image of all sectors (used and unused).

    My question is: If I, sometime in the future, use this image to correct an error or "refresh" my computer, et al., will the unused sectors be filled with zeros?

    Thanks
    nozzle
     
  2. TheRollbackFrog

    TheRollbackFrog Registered Member

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    Nozzle, I'm not sure what imaging tool you used, but in my experience (old ACRONIS and IMAGE FOR WINDOWS), if you imaged ALL SECTORS (rather than just USED) or RAW, you will get a full partition of imaged sectors with maximum compression on those wiped sectors.

    Of course, with that image, you will need a partition of at least that physical size to do a restoration of that image... and those "prepared" sectors will return to the surface of the disk.
     
  3. nozzle

    nozzle Registered Member

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    Thank you Mr. Froggy, but I still don't know if the zeroized image would turn my unused sectors into zeros when using it to reimage my partition. The partition would be the same size as the imaged one (same partition).

    nozzle
     
  4. TheRollbackFrog

    TheRollbackFrog Registered Member

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    My experience...

    Took a 100gB partition with 20gB used...

    ZEROed out all unused space, using Jetico's BCWipe (should be the same with any wiper).
    Imaged ALL SECTORS with IFW (and ACRONIS).
    Wrote ALL ONEs in the 100gB prtition.
    Restored the ALL SECTOR imaged partition.

    All the unused sectors were ZEROed upon completion of the restoration. Why? 'Cause the imager was told to image everything, and it used its appropriate compression algorithm to compression code the ZEROed sectors. When restored, all those compressed sectors were in the full image, and were properly decompressed and written upon restoration.

    This was done because the image was ALL SECTOR/RAW/FULL and the imager doesn't know from sector use when dealing with this type of image... it just restores all that it finds in the image.
     
  5. nozzle

    nozzle Registered Member

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    Thanks again Mr. Froggie. I think now I will be able to zeroize my partition in a lot less time by reimaging instead of waiting hours. :)
     
  6. TheRollbackFrog

    TheRollbackFrog Registered Member

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    Using WIPING tools shouldn't take hours... unless the tool is a bit inefficient.

    When I used the Jetico tool, it was quite fast. it would pre-allocated large chunks of unused disk space from Windows then write like a banshee.

    Of course most re-imaging tools are quite efficient as they usually use direct disk I/O to do their writing.

    As I see it, the only real advantage to "zeroing" unused disk space is if you're trying to do the smallest possible ALL SECTOR (RAW) disk image with a tool that provides good compression... or "clean" all unused sectors (prying eyes) when restoring a volume).
     
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