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

[Anthony K]

On 11/05/13 22:56, Rock wrote:
> On Sat, 11 May 2013 21:27:59 +1000, Anthony K wrote:
>
>>   I'd suggest you still make a copy of the disk with dd and
>> work on the image!
> Key questions:
> Q0. Should I boot to my normal Centos 6 OS?
> Q1: Should I format the new USB hard disk with Fdisk?
> Q2: What dd command should I use?
Having read your earlier posts, I believe you are quite capable of 
sorting out Q0 and Q1.  For Q0 though, I normally use pmagic live CD.  
For Q2, I once ran some tests to determine the optimum blocksize to use 
with dd and discovered that anything over 4096 didn't increase 
throughput much.  However, I still use 4M when working with dd to dump a 
hdd image:
dd if=/dev/sda of=/path/to/hdd-image-file.img bs=4M

After dumping the image, refer to testdisk wiki [0] on how to mount the 
image file.  If you require some hand holding working with testdisk, 
please contact me off-list.


Cheers,
ak.

[0] - 
http://www.cgsecurity.org/wiki/TestDisk_FAQ#How_to_open_the_image.dd_file_.3F