Re: Photoscore

[David Wright]

On Mon 28 Nov 2016 at 21:26:17 (+0000), Karlin High wrote:
> On 11/28/2016 2:12 PM, David Wright wrote:
> > So it should be worth booting from a live linux CD to mount the
> > partitions to check their contents, and to reinstall Grub
> > (or whatever you use to boot) into the MBR.
> 
> The thing to do IMMEDIATELY is make a "drive image backup."

That would certainly be the action to take if the drive was giving
disk errors.

> RedoBackup, 
> Clonezilla, Acronis, Macrium - something the copies the entire hard 
> drive and allows restoring it all if something doesn't work out.

I don't know anything about these particular tools. I would use a tool
like GNU ddrescue works its way from good part of the disk to bad
parts, so maximising the amount of data recovered. It keeps a log file
of its actions so that the process can be interrupted. After all,
recovering a large, badly damaged disk can take a very long time.

However, there's no evidence that disk errors have been or will be a
problem. This is just a case of overwriting. And the post said "It is
quite unclear how much, if anything, will be salvageable from his
actual work environment. [...] it is not clear how much of the
original data will still be in there." So its entirely logical to boot
up a live linux CD and attempt to mount the partitions (readonly
naturally) to determine what is "salvageable".

If the partition type is all that has been altered, and not the
filesystem contents, then linux will mount the partition quite
happily. That would be worth knowing. If there's superblock damage,
then an unmounted partition can be fsck'd (checking that the
appropriate fsck honours the -n option, meaning readonly). If the
results are not too bad, then a copy of that partition can be fsck'd
with a repair option.

Some or all of these actions can avoid the need to purchase another
drive of at least the same size, whose cost can be considerable,
and, after downloading a live CD onto a USB stick, could potentially
set a data owner's mind at rest after only a few minutes.

Of course, if you've got the cash, you can just hand the disk or
entire system to a data recovery agency that you trust, who will have
professionals to do the job. But many of us do not live in that world.

> Then if you want to work on hard drive partitionas, I nominate this tool 
> - Parted Magic: https://partedmagic.com/

I don't know anything about this particular tool nor its relationship,
if any, to GParted or GNU Parted, nor why one of the documents on its
web page is headed Using GParted.

... But that does remind me to write that GNU ddrescue also suffers
from having other similarly named programs floating around which may
or may not be good.

Cheers,
David.