[ale] semi [OT] help recovering data from memory card

[David Tomaschik]

On Tue, Oct 18, 2011 at 9:37 PM, Michael H. Warfield <mhw at wittsend.com> wrote:
> On Tue, 2011-10-18 at 08:51 -0700, Boris Borisov wrote:
>> I'm going to follow this post carefully because I have to deal with
>> the same problem :) missing partition information. Actually dmesg
>> gives me message : sd 1:0:0:0: [sda] Assuming drive cache: write
>> through
>> sda: unknown partition table
>> What I am doing now is dd if=/dev/sda of=usb8gb.img just in case. Will
>> take a while with this USB.1.1 that I plugged into it :)
>
> If you get a hard failure, you may want to try dd-rescue on it.  That
> will work around "holes" in the data and continue to recover data.  It's
> what I use for hard drives, though I don't know how well it will work on
> USB flash drives.

I'm not sure whether or not dd-rescue has any benefits on flash media.
 I would think that blocks on flash media are either functional or
dead.  (The idea on dd-rescue being that the disk might be able to
read it on a retried pass.)

Adding the conv=noerror option to dd, however, should have no downside
and has the upside that blocks AFTER the unreadable block will be
read.


-- 
David Tomaschik, RHCE, LPIC-1
System Administrator/Open Source Advocate
OpenPGP: 0x5DEA789B
http://systemoverlord.com
david at systemoverlord.com