I have started to have difficulty mounting a USB external drive that used to work fine.

In fstab I have
$ cat /etc/fstab|grep sdc
/dev/sdc /media/lacie_sdc auto user,rw,noauto 0 0

fdisk -l tells me
$ fdisk -l /dev/sdc

Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdc1 1 121601 976760001 83 Linux

But mount fails
$ mount /dev/sdc /media/lacie_sdc
mount: you must specify the filesystem type

adding the -t flag doesn't help

$ mount -t ext2 /dev/sdc /media/lacie_sdc
mount: wrong fs type, bad option, bad superblock on /dev/sdc,
missing codepage or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

and dmesg tells me
$ dmesg | tail
ASC=0x0 ASCQ=0x0
end_request: I/O error, dev sdc, sector 0
sd 5:0:0:0: SCSI error: return code = 0x8000002
sdc: Current: sense key=0xb
ASC=0x0 ASCQ=0x0
end_request: I/O error, dev sdc, sector 0
VFS: Can't find an ext2 filesystem on dev sdc.
FAT: invalid media value (0x00)
VFS: Can't find a valid FAT filesystem on dev sdc.
VFS: Can't find an ext2 filesystem on dev sdc.

Can anyone suggest what I might try. Formatting the drive is not an option because there is valuable data on it.

have you tried -t vfat , -t ntfs-3g, or else ?

before do anything i suggest that you find another computer first to backup your data.

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Sometimes a "modprobe -r usb-storage" followed by a "modprobe usb-storage" results in the thing mounting automatically. But I don't want to do that each time.

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To me it looks like your filesystem is corrupted? Could it be?

What filesystems did you have on the disk?, how many partitions?
For mount you need to define /dev/scd1 (here 1 standing for the partition) not just /dev/scd. Look with ls -la /dev/scd* what partitions you have? (although the fdisk -l already seems to list only /dev/scd1)

to do some fix disk stuff fsck -y /dev/scd1 for example - probably need sudo for it. You sure it was ext2? No change checking the functionality of the disk on another machine?

Oh what does dmesg say when you just plug in the HD on USB-plug?

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You need to specify the partition
mount /dev/sdc1 /media/lacie_sdc

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Thankx michaelk and Jykke, adding the 1 to indicate partition and not device was the key. I can now mount using

mount /media/lacie

or

mount /dev/sdc1

but strangely not with

mount /dev/sdc1 /media/lacie
mount: only root can do that

I'm not sure why that is, but the relavent fstab entry is
/dev/sdc1 /media/lacie auto user,rw,noauto 0 0

I didn't yet have further mount problems so hopefully there is no corruption issues.

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Because you've got the entry for the drive in fstab and have specified users can mount it ("user" in the fourth column), it can be mounted by a user specifying the drive or mount point, and will be mounted to the appropriate directory. By specifying both the device and directory, it thinks you're trying to mount it to a different directory, something only the root user can do.

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Thanks for the explanation Total-MAdMaN. This clearly exemplifies the total and absolute stupidity of computers to the extent that "it thinks" is clearly being very generous.

peace
FN

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