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#1 2017-12-01 13:29:04

phunni
Member
From: Bristol, UK
Registered: 2003-08-13
Posts: 714

Baffled by disk partitions on old MP3 player

I'm trying to resurrect my old MP3 player (Cowon D2+) for my daughter and I'm a little stuck at trying to mount the onboard drive.

dmesg reports the make and model correctly and tells me that it's sdb, but there is no partition offered for mounting.  I then ran fdisk and printed the partition table and it reported the following:

Disk /dev/sdb: 15.4 GiB, 16533946368 bytes, 32292864 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x6f20736b

Device     Boot      Start        End    Sectors   Size Id Type
/dev/sdb1        778135908 1919645538 1141509631 544.3G 72 unknown
/dev/sdb2        168689522 2104717761 1936028240 923.2G 65 Novell Netware 386
/dev/sdb3       1869881465 3805909656 1936028192 923.2G 79 unknown
/dev/sdb4       2885681152 2885736650      55499  27.1M  d unknown

I'm slightly baffled as to how the disk can have only 15G, but the first partition alone is 544.G in size...

I'm far from clear if this can be recovered properly and mounted and whether or not I can simply reformat any of the partitions - or even re-partition the whole thing to something a little more sensible.

Any suggestions welcome!

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#2 2017-12-02 04:43:27

GenkiSky
Member
Registered: 2017-04-04
Posts: 73
Website

Re: Baffled by disk partitions on old MP3 player

Hmm, that's kind of strange. First, when you say "there is no partition offered for mounting", how do you mean? When you do 'ls /dev/sdb*' , does nothing show up besides /dev/sdb? Either way, could you paste the output of 'sudo file -s /dev/sdb*' ?

fdisk seems to think there's a dos/mbr label/partitioning of course... It's possible there's really no partition table and fdisk is reading garbage. I guess it's possible there's some proprietary/unrecognized label/partitioning/filesystem being used. I'm also curious, is this a disk that came with the player, or some SD card you bought for it?

Last edited by GenkiSky (2017-12-03 01:55:35)

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#3 2017-12-02 18:34:50

phunni
Member
From: Bristol, UK
Registered: 2003-08-13
Posts: 714

Re: Baffled by disk partitions on old MP3 player

GenkiSky wrote:

how do you mean? When you do 'ls /dev/sdb*' , does nothing show up besides /dev/sdb?

Nothing else - exactly as you say.

GenkiSky wrote:

could you paste the output of 'ls /dev/sdb* | xargs sudo file -s' ?

/dev/sdb: DOS/MBR boot sector, code offset 0x58+2, OEM-ID "TC_MEDIA", sectors/cluster 16, reserved sectors 1250, Media descriptor 0xf8, sectors/track 63, heads 255, sectors 32290650 (volumes > 32 MB), FAT (32 bit), sectors/FAT 15759, serial number 0x0, label: "D2         "

This the internal memory that is physically inside the player and came with it. It can take an SD card, but there isn't one in it at present.

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#4 2017-12-02 18:42:53

Trilby
Forum Fellow
From: Massachusetts, USA
Registered: 2011-11-29
Posts: 17,588
Website

Re: Baffled by disk partitions on old MP3 player

phunni wrote:

I'm slightly baffled as to how the disk can have only 15G, but the first partition alone is 544.G in size...

Not really baffling.  The device likely does not have a partition table at all, so when you run fdisk on it, fdisk reads the region of the device where a partition table would be but instead gets random bits.  These random bits are interpreted as a partition table that has the values that fdisk showed you.

If you are lucky, there may be a known filesystem on the device itself (try to mount /dev/sdb not /dev/sdb1).  If you are unlucky, the data may be in some proprietary filesystem in which case it's only useful in the music player that created it.


Resist the GNU world order.

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#5 2017-12-02 23:09:17

B1omman
Member
Registered: 2016-02-16
Posts: 1

Re: Baffled by disk partitions on old MP3 player

Ok, typed up a response before but that is lost since my keyboard died on me and access was lost, anyways:

Good info on the device: https://www.rockbox.org/wiki/CowonD2Info

You are trying to partition a Nand flash: http://read.pudn.com/downloads106/sourc … 0M_0.7.pdf

Good luck, now I got to try save my daily driver!

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