USB flash stick attaches but mount fails
When I plug-in my 16GB Alcor Micro Corp. Flash Drive into my openSUSE 13.2 (Linux 3.16.7-35-desktop x86_64 GNU/Linux) system, I get the following from journalctl -f:
kernel: scsi 25:0:0:0: Direct-Access Generic USB Flash Disk 7.76 PQ: 0 ANSI: 4
kernel: sd 25:0:0:0: Attached scsi generic sg2 type 0
kernel: sd 25:0:0:0: [sdb] Attached SCSI removable disk
but fdisk -l only shows /dev/sda1 through /dev/sda7 - no /dev/sdbX; and it can't find /dev/sdb, either:
jsn-dev:/home/jan # /usr/sbin/fdisk /dev/sdb
Welcome to fdisk (util-linux 2.25.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
fdisk: cannot open /dev/sdb: No medium found
The USB subsystem does seem to find it, however:
jsn-dev:/home/jan # lsusb
Bus 002 Device 004: ID 0451:8044 Texas Instruments, Inc.
Bus 002 Device 003: ID 0451:8044 Texas Instruments, Inc.
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 002: ID 0451:8046 Texas Instruments, Inc.
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 004: ID 046d:c326 Logitech, Inc.
Bus 003 Device 003: ID 0451:8044 Texas Instruments, Inc.
Bus 003 Device 002: ID 04ca:0061 Lite-On Technology Corp.
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 058f:1234 Alcor Micro Corp. Flash Drive <--
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
I can't write over the partition table with dd also fails:
jsn-dev:/home/jan # dd if=/dev/zero of=/dev/sdb
dd: failed to open ‘/dev/sdb’: No medium found
I have tried all the USB ports in my Dell T7610 system with the same results.
Any ideas how I can debug this further?
The stick is mostly dead.
No Medium Found basically means that the controller cannot "get in touch" with the storage memory. One of the cases is, for example, a card reader without a card inside it.
If you're "lucky" enough, the stick you got can actually be a "fake" flash drive that is actually a microSD + reader:
You can see that the solid half of the type-A USB plug has two layers, and the thicker layer is actually a microSD.
In this case, you can try to "pick" the card out with, for example, a "thin" slotted screwdriver:
Then you might get in return a working microSD with all the data intact.
But of course, you do not want to do this if it still got warranty and you prefer a replacement than the data.