I have a 4TB drive that was originally in a PC connected via SATA. I now wish to put it in an external enclosure and connect it via USB, however this is proving more difficult than I expected, and from what I understand it's Windows XP's fault.
On attempting to mount the drive with sudo mount /dev/sdc /mnt, I receive the following error:
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error.
The output of fdisk -l is as follows:
Disk /dev/sdc: 3.64 TiB, 4000787025920 bytes, 976754645 sectors
Disk model: Expansion Desk
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x00000000
Device Boot Start End Sectors Size Id Type
/dev/sdc1 1 4294967295 4294967295 16T ee GPT
As can be seen, the disk is detected correctly as a 3.64TiB drive, but there is a partition that's read as 16TB. This, AFAIK, is because the sectors are incorrectly read as 4096 bytes long when they should be 512 bytes, and this is a thing that external enclosures do to ensure MBR compatibility with Windows XP.
I tried overcoming this by mounting as follows:
$ sudo mount -o ro,offset=$((1*512)) /dev/sdc1 /mnt
however now I have a new error:
mount: /mnt: failed to setup loop device for /dev/sdc1.
Trying to mount with sudo mount /dev/sdc1 /mnt only yields
mount: /mnt: special device /dev/sdc1 does not exist.
I'm at a loss as to how to mount this drive - at least, without reformatting it. Is it at all possible? Once I've cracked the code, can I configure /etc/fstab to do it automatically for me, or am I stuck in this limbo-land where I have data on my disk that's only readable with a hacky workaround? As a last resort, I think I can plug it back in via SATA, copy all 4TB off, plug it in via USB, reformat it and copy everything back on, but I want to avoid that hassle.
Edit: Output of fdisk -l when connected via SATA. Note the sector size is now 512 and the drive mounts happily.
Disk /dev/sdb: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Disk model: HGST HDN724040AL
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 5852E3A7-A2E4-4589-9D93-F8020C2D7E54
Device Start End Sectors Size Type
/dev/sdb1 2048 7814035455 7814033408 3.7T Linux filesystem
i have a some sata->usb adapters/enclosures/docks that can't be used with > 2tb drives or with 4Kn (native 4k sectors, no 512 emulation) drives. i also have a 2-bay cheap nas that can only do 2x1tb or smaller and there's no new firmware or hacks to 'fix' it even though it's linux under-the-hood.
start with hooking it back up to sata to copy anything on it you want elsewhere, check the filesystem, and run the extended diagnostics.
This is the most likely problem. There is no way the output from fdisk should be different between the two connections (the USB and SATA) if they are both working correctly.
Probably I'm wrong, but it feels like nobody has read the post. As I understand it's not a problem between 2 computers, but 1 computer and the drive being connected over USB with an enclosure or normally through SATA.