[gmx-users] Recover corrupted files from DVD

[Stéphane Téletchéa]

Nuno Ricardo Loureiro Ferreira a écrit :
> Hi *
>  
> I burned several DVD's during a project (and deleted the original files 
> after having verified the saved data, no disk space ;-), and today I 
> just realized that I'm having problems getting the data from one of 
> them, and unfortunely corresponds more or less to the middle of a 
> certain trajectory.

To really do a backup, you'll need to follow those rules:

1 - two different places (think about fire or water)
2 - tow different media types (hard drive and removable media like 
CD/DVD, USB key, ...)
3 - do it on a regular basis

> Do you guys think that running again that missing part of the traj from 
> the last saved .trr, will give me the same results?
> It was run on a box that I no longer have access. Do the trajs done in 
> different boxes give different (or slightly different) trajs using the 
> same gmx version?

If you find another computer with the same architecture, you may do it 
(for instance if you did it on a mono-processor AMD/Intel, it should 
work, assuming you're getting the same random seed). If the job was done 
using multi processors (2 or more), you're dead, cpu roundoff, network 
errors lead to some differences.

> BTW, do you recommend any soft that I can use to try to try to recover 
> files froma CD/DVD (iso9600)?

You can try dd:

dd if=/dev/hdc of=importantdata.iso

Mount the resulting file:

mount -o loop importantdata.iso /mnt/iso

And try to visualize/repair the files appearing under /mnt/iso (trajconv 
may help ?). By chance it is possible that only some frames only are 
missing or corrupted, and you should be able te recover most of the rest 
(and reconcatenate them).

> Best regards,
> Nuno

I hope it'll help you,

Cheers,

Stéphane

-- 
Stéphane Téletchéa, PhD.                  http://www.steletch.org
Unité Mathématique Informatique et Génome http://migale.jouy.inra.fr/mig
INRA, Domaine de Vilvert                  Tél : (33) 134 652 891
78352 Jouy-en-Josas cedex, France         Fax : (33) 134 652 901