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Re: Need Help restoring a filesystem on an external drive WD 'My Book'




On 11/26/17 01:37, bd wrote:
WD P/N : WD10000H 1Q

S/N : WCAU4D 164675

is about 4 or 5 years old. It is an external drive using external power supply. At start, I had formatted it in ext3, so that I 'd be able to storage videofiles larger than 2 Gb. Since then, I storaged a number of files in several directories, subdirectories etc.. I never had any problem until now.

This drive no longer mounts.

Were there any events immediately prior to this change -- power outage, dropped the external drive, updated software, installed software, changed system configuration settings, etc.?


It does not mount automatically as it used to, and I don't know how to mount it manually. My other similar drives mount on /dev/sdb1 or /dev/sr0... depending on to which computer I mount it. In case it doesn't automatically mount, I just type :

#mount /dev/sdb1 /media/bd/ext

and it works

That incantation might work, if the external drive is assigned to /dev/sdb by the kernel, the HDD has a partition table, the ext3 file system is in the first partition, and the directory /media/bd/ext exists. But, the /media directory is usually managed by automount software, so messing with it could cause problems. I typically put my mount points under /mnt.


but right now I don't know for sure the device name to mount.

If I list my /dev directory using ls -lt, I can see what new device appears in the list whenever I plug my external drive. It shows 'sdb'. Not 'sdb1' as for other external drives, just 'sdb'. If now I type :

# mount /dev/sdb /media/bd/ext

That would be correct only if you put the ext3 file system directly on the raw drive without a partition table. As you stated it used to mount automatically, that implies a partition table. Therefore, this incantation is likely wrong.


this gets the external drive to react : the light goes up and down for awhile, and then I get this message :

'you must specify the filesystem'

But, if I try :

# mount -t ext3 /dev/sdb /media/bd/ext

I get this : 'wrong fs type, bad option, bad superblock on /dev/sdb…'

Also, likely a wrong incantation.


same result if I try mounting on 'fat', 'msdos'… filesystems, but I doubt if there are any FAT or msdos space left on this device since I had reformated it to ext3.

At last, I tried :

# fsck /dev/sdb (the external drive starts to light, then :

'fsck ext2 : superblock invalid. Trying to backup blocks

fsck ext2 : bad magic number in superblock while trying to open /dev/sdb

Also, likely a wrong incantation; and dangerous. Hopefully, fsck(8) didn't overwrite any bits on disk.


Now, if I type :

cat /proc/scsi/scsi

I get this :

scsi0 ATA MAXTOR STM

scsi1 ATA MAXTOR STM

scsi5 WD My Book Direct Access

So, the kernel can see the drive at least part of the time.


/etc/fstab

does not show any sdb device

/etc/fstab typically contains entries created by the installer and by the system administrator (you). Automatic mounting should not modify this file.


How am I to get this drive back to operation, or, at least, to recuperate the datafiles that are stored in that WD external drive ?

Thanks in advance to tell me what diagnosis and repair tools I could use

All the software in the world won't help you if the hardware is failing -- the external power supply could be bad, the electronics in the plastic box could be bad, or the drive could be bad. I've seen all three.


Download and run WD's Data Lifeguard Diagnostic to verify the external drive:

   https://support.wdc.com/downloads.aspx


Reply with the results.


David