[gentoo-user] Re: Corrupt xD card with photos

[Sven Köhler]

> I was handed what seems to be a corrupt xD flash card to extract the last
> photo from it.  When the WinXP system at work coughed and died on it
> (couldn't read it) I thought that my Linux would do better.  Anyhow, I've
> inserted it into my Fuji camera and this is what dmesg shows:
>
> ===================================================
> usb 2-1: new full speed USB device using uhci_hcd and address 4
> usb 2-1: configuration #1 chosen from 1 choice
> scsi2 : SCSI emulation for USB Mass Storage devices
> usb-storage: device found at 4
> usb-storage: waiting for device to settle before scanning
>   Vendor: FUJIFILM  Model: USB-DRIVEUNIT     Rev: 1.00
>   Type:   Direct-Access                      ANSI SCSI revision: 00
> SCSI device sda: 256000 512-byte hdwr sectors (131 MB)
> sda: Write Protect is off
> sda: Mode Sense: 07 00 00 00
> sda: assuming drive cache: write through
> SCSI device sda: 256000 512-byte hdwr sectors (131 MB)
> sda: Write Protect is off
> sda: Mode Sense: 07 00 00 00
> sda: assuming drive cache: write through
>  sda: unknown partition table
> sd 2:0:0:0: Attached scsi removable disk sda
> sd 2:0:0:0: Attached scsi generic sg0 type 0
> usb-storage: device scan complete
> ====================================================

First thing that i see is:
where the hell is /dev/sda1? Yes, there should be a FAT partition on
that xD card, but it's not there.

So first step:
Re-create a primary FAT partition without formatting it (for example use
cfdisk)

> Mount fails:
> ====================================================
> $ mount /dev/sda
> mount: wrong fs type, bad option, bad superblock on /dev/sda,
>        missing codepage or other error
>        In some cases useful info is found in syslog - try
>        dmesg | tail  or so
> ====================================================
>
> and dmesg then shows:
> ====================================================
> FAT: bogus number of reserved sectors
> VFS: Can't find a valid FAT filesystem on dev sda.
> FAT: bogus number of reserved sectors
> VFS: Can't find a valid FAT filesystem on dev sda.
> ====================================================
>
> This is what fdisk shows:
> ====================================================
> # fdisk /dev/sda
> Device contains neither a valid DOS partition table, nor Sun, SGI or OSF
> disklabel
> Building a new DOS disklabel. Changes will remain in memory only,
> until you decide to write them. After that, of course, the previous
> content won't be recoverable.
>
> Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
>
> Command (m for help): p
>
> Disk /dev/sda: 131 MB, 131072000 bytes
> 5 heads, 50 sectors/track, 1024 cylinders
> Units = cylinders of 250 * 512 = 128000 bytes
>
>    Device Boot      Start         End      Blocks   Id  System
>
> Command (m for help):
>
> ====================================================
>
> Is there a Linux (or even M$Windoze?) way of me recovering the last photo,
> that doesn't involve reconstructing raw data with a hexeditor?

Maybe your are abled to mount the FAT partition after you "fixed" the
partition table. Well, "fixing" it basically means: delete it, and
create a new one. Typically, the FAT partition simply comsumes the whole
disk. There should be a fair chance, that (c)fdisk chooses the same
start/end-sectors for the partition like any other tool (including the
camera).

Good luck!