I've an USB key that I want to format, but I can't :

* format it in command line :

Results:

```
$ sudo mkfs.ext2 /dev/sdb
mke2fs 1.42.9 (4-Feb-2014)
/dev/sdb is entire device, not just one partition!
Proceed anyway? (y,n) y
mkfs.ext2: Permission denied while trying to determine filesystem size
$ sudo mkfs.ext2 /dev/sdb1
mke2fs 1.42.9 (4-Feb-2014)
Could not stat /dev/sdb1 --- No such file or directory

The device apparently does not exist; did you specify it correctly?

```

* create a partition :

Results:

```
$ sudo fdisk /dev/sdb
fdisk: unable to open /dev/sdb: No medium found

```

* see it in GParted or in USB Stick Formatter
* see a the partition with `ls -l /dev/sd*`

Results:

```
$ ls -l /dev/sd*
brw-rw---- 1 root disk 8,  0 Jan  4 14:43 /dev/sda
brw-rw---- 1 root disk 8,  1 Jan  4 12:07 /dev/sda1
brw-rw---- 1 root disk 8,  2 Jan  4 14:43 /dev/sda2
brw-rw---- 1 root disk 8,  5 Jan  4 11:22 /dev/sda5
brw-rw---- 1 root disk 8, 16 Jan  4 12:30 /dev/sdb

```

* read from it

Results:

```
$ sudo dd if=/dev/sdb of=/tmp/xxx bs=512 count=1
dd: failed to open ‘/dev/sdb’: No medium found
$ sudo dmesg | tail
[22002.140008] usb 2-1.4: new high-speed USB device number 12 using ehci-pci
[22002.238743] usb 2-1.4: New USB device found, idVendor=090c, idProduct=3000
[22002.238748] usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[22002.238750] usb 2-1.4: Product: SM3252A MEMORY BAR  
[22002.238752] usb 2-1.4: Manufacturer: Silicon Motion,Inc. 
[22002.239190] usb-storage 2-1.4:1.0: USB Mass Storage device detected
[22002.239430] scsi37 : usb-storage 2-1.4:1.0
[22003.238585] scsi 37:0:0:0: Direct-Access              USB MEMORY BAR   1000 PQ: 0 ANSI: 0 CCS
[22003.241074] sd 37:0:0:0: Attached scsi generic sg2 type 0
[22003.246714] sd 37:0:0:0: [sdb] Attached SCSI removable disk

```

* find it using `fdisk` :

Results:

```
$ sudo fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x2aa8f047

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048   362375167   181186560    7  HPFS/NTFS/exFAT
/dev/sda2       362378205   823732874   230677335    f  W95 Ext'd (LBA)
Partition 2 does not start on physical sector boundary.
/dev/sda5       362378268   823732874   230677303+   7  HPFS/NTFS/exFAT
Partition 5 does not start on physical sector boundary.

```

`fdisk -l /dev/sdb`

```
$ sudo fdisk -l /dev/sdb
Cannot open /dev/sdb

```

* see it with `sudo cat /proc/partitions`

Results :

```
$ sudo cat /proc/partitions
major minor  #blocks  name

   7        0    1548652 loop0
   8        0  488386584 sda
   8        1  181186560 sda1
   8        2          1 sda2
   8        5  230677303 sda5
  11        0    1593088 sr0

```

* find any errors with `dmesg | tail` :

Results:

```
$ sudo dmesg | tail
[ 5519.189351] usb 2-1.4: new high-speed USB device number 10 using ehci-pci
[ 5519.288491] usb 2-1.4: New USB device found, idVendor=090c, idProduct=3000
[ 5519.288498] usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 5519.288502] usb 2-1.4: Product: SM3252A MEMORY BAR  
[ 5519.288505] usb 2-1.4: Manufacturer: Silicon Motion,Inc. 
[ 5519.289008] usb-storage 2-1.4:1.0: USB Mass Storage device detected
[ 5519.289150] scsi35 : usb-storage 2-1.4:1.0
[ 5520.292225] scsi 35:0:0:0: Direct-Access              USB MEMORY BAR   1000 PQ: 0 ANSI: 0 CCS
[ 5520.292771] sd 35:0:0:0: Attached scsi generic sg2 type 0
[ 5520.294124] sd 35:0:0:0: [sdb] Attached SCSI removable disk

```

And yet I see all the proper information (Manufacturer, ...) about it.

Any suggestions?