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Re: Some help with dd backing up into an iso




On Tue 07 Mar 2017 at 00:11:00 (+0000), GiaThnYgeia wrote:
> I am not very confident I am doing this right and it seems wrong,  I
> can't locate any documentation that results into proper options.
> I tried backing up an 8gb USB that has 2 partitions in it, one had 1.7gb
> of data on it.
> I used dd if=/dev/sdb of=usbfilename.iso
> The resulting image was the full size of the disk.

…and various people have commented on what that actually does,
and better methods of achieving it.

> To test the validity I restored reversing the order of the filenames
> if/of  but that took for ever and it was a hog on resources.  After a
> while I just gave up and killed the process.  I looked at the disk and
> it seemed complete with all files in tact, so maybe I killed it
> somewhere in the verification process.

But only Thomas has mentioned what might be expected as the result of
this action, and no one has pointed out the recklessness of the
action in the first place.

Making a backup and then immediately copying it back over the top of
the original is an obvious recipe for data-loss. And how would this
second operation test the validity? What's the criterion for pass/fail?

Cheers,
David.