do you have any spare harddisk lying around?
if yes, open the USB case and replace the harddisk to see if the WD one is broken (most likely) or if its the case's USB-to-IDE converter.
tell your teacher to replace the broken part
]]>You can always try to mount the partition blindly but that may not work, you can do it with:
mkdir my_ext_disk
mount -o offset=n*512 /dev/sda my_ext_disk
where n is an integer (and do the math don't just put 63*512 ), a good value to start is 63
If nothing works and if no program can recover any data from the drive (if there is anything important there) then this _may_ get you an usable drive again:
as root or with sudo do:
dd if=/dev/zero of=/dev/sdb bs=512 count=1
Then give fdisk a try again.
This clears _just_ the mbr so the disk should look brand new (with no partitions of course), if any of the tools start working again then try recovering any important data.
On the other hand for sfdisk to complain .... sfdisk should be able to do something with it unless what got written to the mbr is something really weird.
If nothing really works I guess that disk may be dead, if it is under warranty do claim it otherwise I would try plugging it inside a desktop pc.
If you manage to do this - then you can try to mount it it with 'auto' as filetype (which is the default for the mount command) and check /etc/mtab for what kind of filesystem is on it. If it turns out to be ntfs, you need to umount and remount with ntfs-3g to make it writable.
But - seeing fdisk doesn't seem to recognize the disk as a valied block device - I'm afraid the disk is a goner ... :-(
]]>/dev/sdb: unrecognised disk label
/dev/sdb: unrecognised disk label
Input/output error during read on /dev/sdb
Input/output error during write on /dev/sdb
/dev/sdb: unrecognised disk label
so is there anyway for me the make the disk label recognizable. And how do I fix the read write error on my I/O device.
]]>sfdisk: read error on /dev/sdb - cannot read sector 0
/dev/sdb: unrecognized partition table type
That says it all.
The problem appears to be with the Master Boot Record (MBR). The MBR resides in Sector 0, and holds the primary partition table. You could just try reformatting the disk (if the data is expendable) or I would also suggest searching the Western Digital HDD page for a tool to test the drive and try a low level format if available. My guess is the issue is a defective drive.
]]>Unable to read /dev/sdb
After that command I dmesg | tail
sd 2:0:0:0: [sdb] Unhandled sense code
sd 2:0:0:0: [sdb] Result: hostbyte=0x00 driverbyte=0x08
sd 2:0:0:0: [sdb] Sense Key : 0x3 [current]
sd 2:0:0:0: [sdb] ASC=0x11 ASCQ=0x0
end_request: I/O error, dev sdb, sector 0
sd 2:0:0:0: [sdb] Unhandled sense code
sd 2:0:0:0: [sdb] Result: hostbyte=0x00 driverbyte=0x08
sd 2:0:0:0: [sdb] Sense Key : 0x3 [current]
sd 2:0:0:0: [sdb] ASC=0x11 ASCQ=0x0
end_request: I/O error, dev sdb, sector 0
I already had the directory made and it requires me to define the type of partitions. When i put mount -t vfat /dev/sdb1 /media/test :
mount: special device /dev/sdb1 does not exist
and dmesg reads after this command the same as above.
sudo sfdisk -s
/dev/sda: 39070080
/dev/sdb: 78150744
total: 117220824 blocks
sudo sfdisk -l
Disk /dev/sda: 4864 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sda1 0+ 61 62- 497983+ 83 Linux
/dev/sda2 62 185 124 996030 83 Linux
/dev/sda3 186 3785 3600 28917000 83 Linux
/dev/sda4 * 3786 4863 1078 8659035 7 HPFS/NTFS
Disk /dev/sdb: 76319 cylinders, 64 heads, 32 sectors/track
read: Input/output error
sfdisk: read error on /dev/sdb - cannot read sector 0
/dev/sdb: unrecognized partition table type
No partitions found
(note that the majority (if not all) external hd's have at least _one_ partition on them)
You could try:
fdisk -l /dev/sdb
to see the partition table
sudo mount -t ntfs-3g /dev/sdb /media/test and
sudo mount -t vfat /dev/sdb /media/test
cfdisk does not detect sdb and niether does gparted. parted does but can't do anything with it.
dmesg | tail
sd 2:0:0:0: [sdb] Result: hostbyte=0x00 driverbyte=0x08
sd 2:0:0:0: [sdb] Sense Key : 0x3 [current]
sd 2:0:0:0: [sdb] ASC=0x11 ASCQ=0x0
end_request: I/O error, dev sdb, sector 0
sd 2:0:0:0: [sdb] Unhandled sense code
sd 2:0:0:0: [sdb] Result: hostbyte=0x00 driverbyte=0x08
sd 2:0:0:0: [sdb] Sense Key : 0x3 [current]
sd 2:0:0:0: [sdb] ASC=0x11 ASCQ=0x0
end_request: I/O error, dev sdb, sector 0
FAT: unable to read boot sector
lsusb
Bus 005 Device 001: ID 1d6b:0001
Bus 004 Device 001: ID 1d6b:0001
Bus 003 Device 001: ID 1d6b:0001
Bus 001 Device 002: ID 1058:0701 Western Digital Technologies, Inc.
Bus 001 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0001