Re: DD bs=4M option on USB mem-stick creates false format

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

kAt wrote:
> > /sbin/fdisk -l /dev/sdb
> Disk /dev/sdb: 7.2 GiB, 7751073792 bytes, 15138816 sectors

Is this about the correct size of the stick ?


> Units: sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes

Looks like a normal block size for USB sticks and conventional disks.


> Device     Boot   Start     End Sectors  Size Id Type
> /dev/sdb1  *         64 1374207 1374144  671M  0 Empty
> /dev/sdb2       1297212 1298619    1408  704K ef EFI (FAT-12/16/32)

This is the MBR partition table. You may use fdisk to add a partition.
(Let's hope it will not hate that sdb2 is located inside sdb1.)


> echo 2 | sudo /sbin/gdisk -l /dev/sdb
> Warning! Main partition table overlaps the first partition by 64 blocks!
> You will need to delete this partition or resize it in another utility.

gdisk definitively hates the start of the outer partition.
But starting at block 64 would mean that it would not be mountable.

> Number  Start (sector)    End (sector)  Size       Code  Name
>   2         1297212         1298619   704.0 KiB   0700  ISOHybrid1

The EFI partition is more to its taste.

As said, the GPT of an ISO with "mjg" layout is quite useless
and i'd zeroize its header block at block address 1.


Have a nice day :)

Thomas