advice for data recovery

[Robin Laing]

Dave Stevens wrote:
> Hello All,
> 
> I am trying to recover .jpgs that were on a SATA drive that was formatted by 
> mistake. No backup of course. Foremost has done a wonderful job of recovering 
> several tens of thousands of files. Unfortunately many of them are either 
> irrelevant (cached web fragments, etc.) or damaged. The most common type of 
> damage is shown when trying to view them in Nautilus, when I get a message 
> saying, "unsupported marker type."
> 
> It seems about 30% - 40% of the files recovered are damaged in this way.
> 
> They aren't my images and I am not able to gauge what is worthwhile or not but 
> I would like to do some triage by only considering those of a certain minimum 
> size (easy to do) and not damaged (no idea.)
> 
> So does anyone know of a program I can use to only copy files that are not 
> damaged? I can sort out the teenies, but don't see how to proceed after that.  
> 
> TIA.
> 
> Dave
> 

My sympathies.  I did the same thing.  I did a backup but forgot one sub 
folder.  Shame on me.

In the recovery, I ended up with 180Gigs of recovered files to go 
through.  Not pleasant.

I have not found a program that can check and confirm the accuracy of 
the recovered files as they are all listed as images if I type in
    file {file name}

What I have done is use "GQview" and look at the thumbnails.

My procedure is/was this.

With all the recovered images, I wrote a short bash script to sort them 
into smaller sub-directories.  This cut the number of images down to 10K 
or 20K per directory.

Next I opened the directory in GQview.  With thumbnails turned on, this 
takes minutes, depending on the size of the folder.

I then sort the directory by file size.  This helps to eliminate smaller 
files from having to be viewed.  I guess I could write a script to rm 
these files anyway.  See later.

Now with the thumbnails, I can quickly scan the directory for images.  I 
will use the mouse to drag and drop the file in the parent directory. 
When scanning, the scrolling slows/stops for real images over corrupted 
files.

I know my images from my camera are larger than 2M each but the recovery 
software would pull any images it can and thus I sometimes have 
recovered a smaller version of the image where the full image is gone.

I still have over 100Gig to go through.

I now backup my photos to DVD as soon as I take them off the stick.

One note about recovery software.  As I did this at home, I cannot 
remember what program I used.  But what I did find out was it didn't 
look at the headers for the images from my camera.  I needed to change 
the header info in a configuration file.  I did a test on a memory stick 
to ensure I was looking at my images.

-- 
Robin Laing