The Mystery of Disk imaging

@WYC999

Referring to quality.. I'm not sure what you mean by quality?

And typically most imaging programs provide a built-in verification or tester. They can read back the image, decompress it, and do all operations EXCEPT writing it back to the disk.

On new installs and setups. I typically do that, then I do a full-on actual real restore. I try to test it when the system hasn't been used yet, so if it messes up, it's early in the game and I can re-build without critical data loss.

A sector-by-sector backup or drive clone or sector-by-sector image should mean you are grabbing each and every sector, used or un-used. No questions asked. This is filesystem independent. And it would grab all sectors from 0 to 312,576,642. All of them.

The term image used by itself can mean many different things. The backup program may only grab files that are in the directories and MFT on NTFS systems. Or it may just do a certain partition.

Unfortunately in this industry terms and definitions are being bandied about with more abandon than ever. And you sometimes have to very specifically state something in exhausting detail. Just like in the old days!

 

Hi Mudcrab,

No actually i was aware from the beginning of what unused vs. unallocated is.

But one thing i noticed: After your definition, would a raw backup of a DRIVE include UNALLOCATED Space or not? So to ask: Is it really sector-by-sector?

Greetings to you and all of ya...

 

Hi Keatah,

"A sector-by-sector backup or drive clone or sector-by-sector image should mean you are grabbing each and every sector, used or un-used. No questions asked. This is filesystem independent. And it would grab all sectors from 0 to 312,576,642. All of them."

This depends (as you state later) in my experience strongly on which software you use (and how this special software defines the terms). For example i have been a long time acronis user and here it would look like:

image: means for TIH 2011 to backup only the used sectors of all PARTITIONS - leaving unallocated space out.

sector-by-sector image: Backing up additionally the unused space of partitions

unallocated space: you would have to check this option if you want to backup additionally the unallocated space.

On the idea of testing the "quality of the image with the imaging software": Yeah i know in the beginning of the thread i was looking more for a method to validate the image with an independent tool that comes not from the same company. Independent review you know. But that's not so much my concern now, since this is an easy task it would be weird if there would be many errors in it.