Failure to dd diskboot.img to pen drive

Phil Meyer pmeyer at themeyerfarm.com
Thu Nov 15 21:43:39 UTC 2007


Rick Stevens wrote:
> On Thu, 2007-11-15 at 18:08 -0200, Clodoaldo wrote:
>   
>> I want to install F8 from a 1GB pen drive but dd does not work,
>> although I can mount it. dd shows it worked:
>>
>> # dd if=/home/cpn/Desktop/Downloads/diskboot.img of=/dev/sdb1
>> 24576+0 records in
>> 24576+0 records out
>> 12582912 bytes (13 MB) copied, 0.307408 s, 40.9 MB/s
>>
>> But there is nothing in the directory:
>>
>> [root at dkt ~]# ll /media/KINGSTON/
>> total 0
>>
>> fdisk -l shows strange messages:
>>
>> # fdisk -l
>>
>> Disk /dev/sda: 81.9 GB, 81964302336 bytes
>> 16 heads, 63 sectors/track, 158816 cylinders
>> Units = cylinders of 1008 * 512 = 516096 bytes
>>
>>    Device Boot      Start         End      Blocks   Id  System
>> /dev/sda1   *           1         203      102280+  83  Linux
>> /dev/sda2             204      158816    79940952   8e  Linux LVM
>>
>> Disk /dev/sdb: 1027 MB, 1027604480 bytes
>> 32 heads, 62 sectors/track, 1011 cylinders
>> Units = cylinders of 1984 * 512 = 1015808 bytes
>>
>> This doesn't look like a partition table
>> Probably you selected the wrong device.
>>
>>    Device Boot      Start         End      Blocks   Id  System
>> /dev/sdb1   ?      966294     1813487   840415161   69  Unknown
>> Partition 1 has different physical/logical beginnings (non-Linux?):
>>      phys=(612, 109, 33) logical=(966293, 30, 10)
>> Partition 1 has different physical/logical endings:
>>      phys=(255, 97, 46) logical=(1813486, 20, 39)
>> Partition 1 does not end on cylinder boundary.
>> /dev/sdb2   ?      976282     1834012   850868148+  ff  BBT
>> Partition 2 has different physical/logical beginnings (non-Linux?):
>>      phys=(367, 115, 35) logical=(976281, 15, 17)
>> Partition 2 has different physical/logical endings:
>>      phys=(80, 13, 10) logical=(1834011, 14, 55)
>> Partition 2 does not end on cylinder boundary.
>> /dev/sdb3   ?      891259     1782449   884061367   6c  Unknown
>> Partition 3 has different physical/logical beginnings (non-Linux?):
>>      phys=(355, 116, 37) logical=(891258, 2, 52)
>> Partition 3 has different physical/logical endings:
>>      phys=(112, 97, 32) logical=(1782448, 31, 27)
>> Partition 3 does not end on cylinder boundary.
>> /dev/sdb4   ?           1     1790834  1776506368    0  Empty
>> Partition 4 has different physical/logical beginnings (non-Linux?):
>>      phys=(10, 114, 13) logical=(0, 0, 1)
>> Partition 4 has different physical/logical endings:
>>      phys=(0, 0, 0) logical=(1790833, 1, 2)
>> Partition 4 does not end on cylinder boundary.
>>
>> Partition table entries are not in disk order
>>
>>
>> When I try to enter fdisk the device can't be opened:
>>
>> # fdisk sdb
>>
>> Unable to open sdb
>>
>> # ll /dev/sdb1
>> -rw-r--r-- 1 root root 12582912 2007-11-15 17:56 /dev/sdb1
>>
>> Any workaround?
>>     
>
> Redo the dd, but do NOT specify a partition, e.g.:
>
> 	dd if=/home/cpn/Desktop/Downloads/diskboot.img of=/dev/sdb
>
> For it to be bootable, the image must be written to the raw device
> (/dev/sdb), not to a partition on the drive (/dev/sdb1).
>   

Good advice, and the OP has only a 1GB pen drive, but for those with a 
4GB or larger pen drive, you have better options.

First slam the broken MBR shipped on most pen drives:

unmount any mounted partitions from the device

# cat /usr/lib/syslinux/mbr.bin >/dev/sdb

($ rpm -qf /usr/lib/syslinux/mbr.bin
syslinux-3.36-7.fc8)

Second, use fdisk to create two partitions on the tumb drive.  The first 
one can be 12 or 13 MB depending on manufacturer.  Make it 13MB to be safe.

Now you can dd the bootdisk.img to the first partition and it will be 
bootable.

Thirdly, format the second partition as FAT32

# mkfs -t vfat -F 32 /dev/sdb2 -n images

copy the Fedora DVD image to the second partition.

Now you have a pen drive that can do the entire install, not just the boot.

CAVEATS:

The USB driver is slow to load.  When you are prompted for the DVD 
image, select HARDRIVE/sdb2 (assuming one drive in the system).  If the 
pen drive is not shown in the list of hard drives, go back and try it 
again.  It can take anaconda 10 seconds to mount the pen drive.

Windows, even the mighty Vista, cannot mount two partitions from a thumb 
drive.  Go Microsoft!  You rock!
Thus making the available space on the second partition unavailable from 
Windows.  Does not bother me, since I have no MS products at all, but it 
does affect some folks.

Good Luck!




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