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I am having some problems with an USB drive that is not working correctly, I am trying to recreate partitions with fdisk or sfdisk but once I do it I do "-l" and there's no partitions.

This is how I ran fdisk:

root:~$ sudo fdisk /dev/sdc

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): p

Disk /dev/sdc: 1020 MB, 1020887040 bytes
32 heads, 61 sectors/track, 1021 cylinders
Units = cylinders of 1952 * 512 = 999424 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-1021, default 1): 
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-1021, default 1021): 
Using default value 1021

Command (m for help): p

Disk /dev/sdc: 1020 MB, 1020887040 bytes
32 heads, 61 sectors/track, 1021 cylinders
Units = cylinders of 1952 * 512 = 999424 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1        1021      996465+  83  Linux

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

And this is how I ran sfdisk:

root:~$ sudo sfdisk /dev/sdc
Checking that no-one is using this disk right now ...
OK

Disk /dev/sdc: 1021 cylinders, 32 heads, 61 sectors/track
Old situation:
Units = cylinders of 999424 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sdc1          0       -       0          0    0  Empty
/dev/sdc2          0       -       0          0    0  Empty
/dev/sdc3          0       -       0          0    0  Empty
/dev/sdc4          0       -       0          0    0  Empty
Input in the following format; absent fields get a default value.
<start> <size> <type [E,S,L,X,hex]> <bootable [-,*]> <c,h,s> <c,h,s>
Usually you only need to specify <start> and <size> (and perhaps <type>).

/dev/sdc1 :
/dev/sdc1          0+   1020    1021-    996495+  83  Linux
/dev/sdc2 :
/dev/sdc2          0       -       0          0    0  Empty
/dev/sdc3 :
/dev/sdc3          0       -       0          0    0  Empty
/dev/sdc4 :
/dev/sdc4          0       -       0          0    0  Empty
New situation:
Units = cylinders of 999424 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sdc1          0+   1020    1021-    996495+  83  Linux
/dev/sdc2          0       -       0          0    0  Empty
/dev/sdc3          0       -       0          0    0  Empty
/dev/sdc4          0       -       0          0    0  Empty
Warning: no primary partition is marked bootable (active)
This does not matter for LILO, but the DOS MBR will not boot this disk.
Do you want to write this to disk? [ynq] y
Successfully wrote the new partition table

Re-reading the partition table ...

If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)
to zero the first 512 bytes:  dd if=/dev/zero of=/dev/foo7 bs=512 count=1
(See fdisk(8).)

But when I run fdisk -l /dev/sdc I see:

root:~$ fdisk -l /dev/sdc

Disk /dev/sdc: 1020 MB, 1020887040 bytes
32 heads, 61 sectors/track, 1021 cylinders
Units = cylinders of 1952 * 512 = 999424 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System

and sfdisk -l /dev/sdc:

root:~$ sudo sfdisk -l /dev/sdc

Disk /dev/sdc: 1021 cylinders, 32 heads, 61 sectors/track
Units = cylinders of 999424 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sdc1          0       -       0          0    0  Empty
/dev/sdc2          0       -       0          0    0  Empty
/dev/sdc3          0       -       0          0    0  Empty
/dev/sdc4          0       -       0          0    0  Empty

The partitions are not saved. Also that is the same output I get when running -l before trying to create the partitions.

I've also tried parted, gparted and other apps that runs on windows. Nothing created any partition.

I am using Ubuntu 10.04 and I have automount media disabled.

Does someone has any idea why is this happening?

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Crazy question - but the USB disk doesn't have a read-only switch on it does it? – ed. Sep 20 '11 at 17:53
    
I have the same problem with cfdisk. – dhill Jun 29 '12 at 9:40
    
Not sure, try running partprobe /dev/sdc – deppfx Jul 26 '12 at 8:24
    
please be more specific is it a flash drive or a real usb hdd? some flash drives are not capible of being partitioned. there are 2 modes in which a flash drive can be built. the way the firmware is written its either treated like a hdd or a special usb mass media device. – Kendrick Aug 21 '12 at 1:09

You have to make it a "fixed disk" first, that is make it act like a normal hard drive. Instructions for winxp: http://www.prime-expert.com/articles/a05/enabling-multiple-partitions-on-removable-usb-storage-devices.php

Similar instructions exist for linux:

http://askubuntu.com/questions/101637/usb-turn-write-protection-off

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