[CentOS] Need a Centos 6 USB hard drive recovery procedure

Mon Jun 3 14:41:29 UTC 2013
Louis Lagendijk <louis at fazant.net>

On Sat, 2013-06-01 at 19:52 +0000, Rock wrote:
> On Sat, 01 Jun 2013 16:40:46 +0000, Rock wrote:
> 
> > Now comes the biggie, backing up the entire 150MB disk:
> > Q: Maybe I should have used the "conv=noerror" option
> > as suggested in the dd wikipedia entry?
> > $ sudo dd if=/dev/sdc1 of=/mnt/image.dd bs=1M
> 
> The dd finished backing up after about 3 hours.
> 
> $ sudo dd if=/dev/sdc1 of=/mnt/image.dd bs=1M
> ==> 152625+1 records in
> ==> 152625+1 records out
> ==> 160039240704 bytes (160 GB) copied, 9750.86 s, 16.4 MB/s
> 
> Although I can't see to change the permissions of the result:
> $ ls -l
> ==> -rwxrwxrwx. 1 root root 160039240704 Jun  1 12:13 image.dd
> $ sudo chmod uog=r /mnt/image.dd
> $ ls -l
> ==> -rwxrwxrwx. 1 root root 160039240704 Jun  1 12:13 image.dd
> $ sudo chmod 555 ./image.dd
> $ ls -l
> ==> -rwxrwxrwx. 1 root root 160039240704 Jun  1 12:13 image.dd
> 
> At this point, some people said to try to recover using 
> the backup; while others said I should work off the original disk.
> 
> I think I'll try the testdisk recover procedure first.
> 
testdik can work on a disk image, so I recommend using that. Don't risk
chaging the original disk (although testdisk is not supposed to touch it
IIRC)
/Louis