[arch-general] Bad Magic Number in Superblock - Any trick for Arch or for new kernels?

[David C. Rankin]

On 06/09/2010 01:16 PM, David C. Rankin wrote:
> The situation:
> 
> 	On reboot - grub 22 error
> 	boot arch install cd 2009-08, cannot mount drive
> 	partition table shows 1 partition /dev/hda1 (PATA drive) (should be 3)
> 	(I can't put my hands on the saved 'fdisk -l' data, it's somewhere)
> 	gparted 0.46 (0.44 wont work) - loads, but only shows a single partition
> 	fsck -> Gives the bad magic number in superblock error, tries backup same error
> 	Booted without issue for over a year

More information:

	I pulled the drive to diagnose it under a running system where I would have
access to logs, etc.., so I have it connected via usb. Here are the errors on
connenct:

Jun  9 14:20:16 alchemy kernel: usb 1-8: new high speed USB device using
ehci_hcd and address 3
Jun  9 14:20:16 alchemy kernel: klogd 1.4.1, ---------- state change ----------
Jun  9 14:20:16 alchemy kernel: usb 1-8: configuration #1 chosen from 1 choice
Jun  9 14:20:16 alchemy kernel: usb 1-8: New USB device found, idVendor=152d,
idProduct=2338
Jun  9 14:20:16 alchemy kernel: usb 1-8: New USB device strings: Mfr=1,
Product=2, SerialNumber=5
Jun  9 14:20:16 alchemy kernel: usb 1-8: Product: USB to ATA/ATAPI Bridge
Jun  9 14:20:16 alchemy kernel: usb 1-8: Manufacturer: JMicron
Jun  9 14:20:16 alchemy kernel: usb 1-8: SerialNumber: 7D457CA67703
Jun  9 14:20:17 alchemy kernel: Initializing USB Mass Storage driver...
Jun  9 14:20:17 alchemy kernel: scsi6 : SCSI emulation for USB Mass Storage devices
Jun  9 14:20:17 alchemy kernel: usb-storage: device found at 3
Jun  9 14:20:17 alchemy kernel: usb-storage: waiting for device to settle before
scanning
Jun  9 14:20:17 alchemy kernel: usbcore: registered new interface driver usb-storage
Jun  9 14:20:17 alchemy kernel: USB Mass Storage support registered.
Jun  9 14:20:18 alchemy kernel: scsi 6:0:0:0: Direct-Access     MDT MD25
00JB-00GVA0      2D08 PQ: 0 ANSI: 2 CCS
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] 488397168 512-byte hardware
sectors (250059 MB)
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] Write Protect is off
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] Mode Sense: 00 38 00 00
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] Assuming drive cache: write
through
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] 488397168 512-byte hardware
sectors (250059 MB)
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] Write Protect is off
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] Mode Sense: 00 38 00 00
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] Assuming drive cache: write
through
Jun  9 14:20:18 alchemy kernel:  sdb: sdb1
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: [sdb] Attached SCSI disk
Jun  9 14:20:18 alchemy kernel: sd 6:0:0:0: Attached scsi generic sg2 type 0
Jun  9 14:20:18 alchemy kernel: usb-storage: device scan complete
Jun  9 14:20:20 alchemy kernel: EXT3-fs error (device sdb1):
ext3_check_descriptors: Block bitmap for group 880 not in group (block 0)!
Jun  9 14:20:20 alchemy kernel: EXT3-fs: group descriptors corrupted!
Jun  9 14:20:29 alchemy kernel: EXT3-fs error (device sdb1):
ext3_check_descriptors: Block bitmap for group 880 not in group (block 0)!
Jun  9 14:20:29 alchemy kernel: EXT3-fs: group descriptors corrupted!

21:21 alchemy:/home/backup/alchemy # cat /proc/partitions
major minor  #blocks  name

   8     0  625131864 sda
   8     1    1542208 sda1
   8     2   83891430 sda2
   8     3          1 sda3
   8     5    2048256 sda5
   8     6   36861111 sda6
   8     7  500786181 sda7
   8    16  244198584 sdb
   8    17  244196001 sdb1

14:24 alchemy:/home/backup/alchemy # tune2fs -l /dev/sdb1 | grep 'Block size'
Block size:               4096

14:25 alchemy:/home/backup/alchemy # e2fsck -y -b 32768 /dev/sdb
e2fsck 1.40.8 (13-Mar-2008)
e2fsck: Device or resource busy while trying to open /dev/sdb
Filesystem mounted or opened exclusively by another program?


	I guess if you can't even open it to check the superblock, things are not good.
What say the experts, is it looking more like a paper-weight at this point? Any
other thoughts?

-- 
David C. Rankin, J.D.,P.E.
Rankin Law Firm, PLLC
510 Ochiltree Street
Nacogdoches, Texas 75961
Telephone: (936) 715-9333
Facsimile: (936) 715-9339
www.rankinlawfirm.com