Error mounting: mount: /dev/sdd1: can't read superblock

[ChannelZ28]

what does this error message mean? im trying to mount an ipod in disc mode. please let me know if there is a way to manually mount it to get around this. but not too technical, please! the simpler the language, the easier i will understand it. thanks!

[Kloschüssel]

Unfortunatly for you I have no iPod, so I cannot say which filesystem they use to store the data on it. So I can give you only a general explanation of the problem.

So said, this error occurs when one tries to mount a ext filesystem, where the primary superblock is corrupt/broken. A superblock would tell the driver where the data can be found on the disc. Without it, the driver won't be able to find any data (file or directory, etc). So the driver just tells you: can't mount, the superblock is broken.

Fortunatly ext decided to write backup superblocks throughout the whole disc every fixed number of sectors. Thus, if the primary fails - may due to hardware error, one can manually trigger the driver to use the backup superblock, if that one is broken too, pick the next and so on. Only if all superblocks (depending on the size of the disc and settings there can be quite a lot of them) are broken, the filesystem is seriously damaged and can be repaired only by reindexing the data inside - which is quite a big effort for a computer and it could take him on a long journey.

Back to your problem and two possible resolutions:

One might be, that the iPod is just not a ext filesystem and you are trying to mount a non-ext filesystem. Naturally he won't find any superblock as the filesystem has none. Tell the mount routine to use the correct driver if it can't detect the filesystem automatically.

The other might be, that the ext filesystem of your iPod was damaged. In this case tell him to pick an alternative superblock and he will be fine.

PS: it might be that you can't mount iPod filesystems at all because apple won't let you do it. I will never have a iPod, so I just can't help you. With the lot of information I gave you, ask google for more information. He will answer you for sure.

[rcgreen]

I'm guessing that your system is attempting to
automatically detect the file system type, and getting it
wrong. Ipods have the HFS+ file system and this can be specified
manually with the mount command.

That would be something along the lines of

mount -t hfsplus <devicename> <mount point>

You supply correct device name and mount point.

[ChannelZ28]

ok thanks, good information. heres a bit more info.

ubuntu normally recognizes my ipod without any trouble. i also use it as an external hard drive. the problem is that i was downloading a torrent directly onto the ipod and it ovefilled the capacity of the ipod. at least i think this is what happened. now my ipod is having issues and i need to get onto it somehow to delete some files so that it has a little spare room to run properly. i dont think there is anything wrong with it, other than it being filled with more data than it has hard drive space.

rcgreen: if ipods use the HFS+ file system, does that mean the information for an ext file system wont be the same?

what would be the mount point?

thanks.

[rcgreen]

It would be necessary for the mount command to specify
-t hfsplus as part of the command. The mount point
would be any place you choose, traditionally in the /mnt
or /media directories. Something like /mnt/ipod
You need to create a directory as a mount point.

If it was usually mounting automatically, you may still have trouble
mounting it now. Good luck.

[ChannelZ28]

i tried it and it gave me a ">" prompt. is there something else i need to put in afterwards?

[devils casper]

Which command did you execute?

sudo mkdir /media/ipod
sudo mount -t hfsplus  device_name  /media/ipod

Replace device_name with the name assigned to ipod. Execute the output of sudo fdisk -l command to check that.

In case nothing works, post the output of sudo fdisk -l command here.

[ChannelZ28]

i entered these commands

sudo mkdir /media/ipod
sudo mount -t hfsplus device_name /media/ipod


and got this response.


> sudo mkdir /media/ipod
> sudo mount -t hfsplus ROSS'S IPOD /media/ipod
Usage: mount -V : print version
mount -h : print this help
mount : list mounted filesystems
mount -l : idem, including volume labels
So far the informational part. Next the mounting.
The command is `mount [-t fstype] something somewhere'.
Details found in /etc/fstab may be omitted.
mount -a [-t|-O] ... : mount all stuff from /etc/fstab
mount device : mount device at the known place
mount directory : mount known device here
mount -t type dev dir : ordinary mount command
Note that one does not really mount a device, one mounts
a filesystem (of the given type) found on the device.
One can also mount an already visible directory tree elsewhere:
mount --bind olddir newdir
or move a subtree:
mount --move olddir newdir
One can change the type of mount containing the directory dir:
mount --make-shared dir
mount --make-slave dir
mount --make-private dir
mount --make-unbindable dir
One can change the type of all the mounts in a mount subtree
containing the directory dir:
mount --make-rshared dir
mount --make-rslave dir
mount --make-rprivate dir
mount --make-runbindable dir
A device can be given by name, say /dev/hda1 or /dev/cdrom,
or by label, using -L label or by uuid, using -U uuid .
Other options: [-nfFrsvw] [-o options] [-p passwdfd].
For many more details, say man 8 mount .




i dont know what any of that means, it looks like its just information and not an actual mount.

[ChannelZ28]

here are the results of "sudo fdisk -l"


Disk /dev/sda: 16.1 GB, 16139681792 bytes
255 heads, 63 sectors/track, 1962 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00005f42

Device Boot Start End Blocks Id System
/dev/sda1 * 1 1875 15052800 83 Linux
/dev/sda2 1875 1963 705537 5 Extended
/dev/sda5 1875 1963 705536 82 Linux swap / Solaris

Disk /dev/sdb: 15.9 GB, 15931539456 bytes
255 heads, 63 sectors/track, 1936 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xe80fe80f

Device Boot Start End Blocks Id System
/dev/sdb1 1 1936 15550888+ c W95 FAT32 (LBA)
Note: sector size is 4096 (not 512)

Disk /dev/sdc: 159.8 GB, 159840301056 bytes
26 heads, 50 sectors/track, 30018 cylinders
Units = cylinders of 1300 * 4096 = 5324800 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x20202020

Device Boot Start End Blocks Id System
/dev/sdc1 1 30019 156093788 b W95 FAT32
Partition 1 does not start on physical sector boundary.



ignore the first two, the third one, 159.8gb is my ipod. but again, i dont really understand the information.

[yancek]

From your first post error message I would expect the device name you need in the mount command would be "/dev/sdd1" because that is what your Ipod was seen as. In the command you posted, replace device_name with /dev/sdd1".

I see you posted again since I started writting this. If your Ipod is the 159GB from your last post, then change the above "dev/sdd1" to "/dev/sdc1" (without quotes. Also, if that is the correct device, it is not an HFS filesystem but your fdisk output shows it as fat32, so replace the hfsplus with "vfat".

The device (sdc1, sdd1) will change when you are plugging/unplugging different devices.