Не создаются разделы на flash

Disk /dev/sdb: 4047 MB, 4047503360 bytes
125 heads, 62 sectors/track, 1020 cylinders, total 7905280 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
Disk identifier: 0x00000000

Disk /dev/sdb doesn't contain a valid partition table

dd: writing to ‘/dev/sdb’: Input/output error
2313+0 records in
2312+0 records out
1183744 bytes (1.2 MB) copied, 6.23992 s, 190 kB/s

Disk /dev/sdb: 4047 MB, 4047503360 bytes
125 heads, 62 sectors/track, 1020 cylinders, total 7905280 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
Disk identifier: 0x00000000

Disk /dev/sdb doesn't contain a valid partition table

Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x8f372dc3.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

Command (m for help): n

Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended

Select (default p): p

Partition number (1-4, default 1): 

Using default value 1

First sector (2048-7905279, default 2048): 
Using default value 2048

Last sector, +sectors or +size{K,M,G} (2048-7905279, default 7905279): 
Using default value 7905279



Command (m for help): t

Selected partition 1
Hex code (type L to list codes): 6
Changed system type of partition 1 to 6 (FAT16)

Command (m for help): p

Disk /dev/sdb: 4047 MB, 4047503360 bytes
125 heads, 62 sectors/track, 1020 cylinders, total 7905280 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
Disk identifier: 0x8f372dc3

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     7905279     3951616    6  FAT16

Command (m for help): w 


The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 5: Input/output error.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)

WARNING: If you have created or modified any DOS 6.x
partitions, please see the fdisk manual page for additional
information.

Error closing file