[gentoo-user] Re: Corrupt USB pen drive

[Francesco Talamona]

On Thursday 17 May 2007, Mick wrote:
> Hi All,
>
> A colleague used a USB stick on his home machine and when he brought
> it to work he can no longer access it using WinXP.  I offered to help
> with my Gentoo laptop (as one ought to rise to the challenge!) but it
> seems that Linux is also struggling to get to it:
> ==========================================
> usb 2-1: new full speed USB device using uhci_hcd and address 2
> usb 2-1: configuration #1 chosen from 1 choice
> scsi0 : SCSI emulation for USB Mass Storage devices
> usb-storage: device found at 2
> usb-storage: waiting for device to settle before scanning
> scsi 0:0:0:0: Direct-Access              USB BAR          1.89 PQ: 0
> ANSI: 2 SCSI device sda: 255744 512-byte hdwr sectors (131 MB)
> sda: Write Protect is off
> sda: Mode Sense: 03 00 00 00
> sda: assuming drive cache: write through
> SCSI device sda: 255744 512-byte hdwr sectors (131 MB)
> sda: Write Protect is off
> sda: Mode Sense: 03 00 00 00
> sda: assuming drive cache: write through
>  sda: unknown partition table
> sd 0:0:0:0: Attached scsi removable disk sda
> sd 0:0:0:0: Attached scsi generic sg0 type 0
> usb-storage: device scan complete
> UDF-fs: No VRS found
> Unable to identify CD-ROM format.
> FAT: bogus logical sector size 65535
> VFS: Can't find a valid FAT filesystem on dev sda.
> NTFS-fs warning (device sda): is_boot_sector_ntfs(): Invalid boot
> sector checksum.
> NTFS-fs error (device sda): read_ntfs_boot_sector(): Primary boot
> sector is invalid.
> NTFS-fs error (device sda): read_ntfs_boot_sector(): Mount option
> errors=recover not used. Aborting without trying to recover.
> NTFS-fs error (device sda): ntfs_fill_super(): Not an NTFS volume.
> hfs: can't find a HFS filesystem on dev sda.
> VFS: Can't find ext3 filesystem on dev sda.
> VFS: Can't find an ext2 filesystem on dev sda.
> ReiserFS: sda: warning: sh-2021: reiserfs_fill_super: can not find
> reiserfs on sda
> ==========================================
>
> I tried to dd the boot sector so that I can look at it on my hard
> drive, but it cannot access /dev/sda.  Is there anything that I can
> do with my Gentoo to recover the files on this USB?

If you have usb support built modular in the kernel it worth a try to 
force the laptopo to USB 1.1 so it can read a reluctant key (I once had 
a key that stopped working on USB 2.0 but was perfectly readable by 
older PCs).

You can then try ddrescue, a dd clone that is specifically designed to 
skip errors on bad media for recovery attempt.

Good luck
	Francesco.

-- 
Linux Version 2.6.21-gentoo, Compiled #1 PREEMPT Mon Apr 30 21:45:34 
CEST 2007
One 1GHz AMD Athlon 64 Processor, 2GB RAM, 2004.01 Bogomips Total
aemaeth
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