On Tuesday 29 Mar 2016 19:53:45 meino.cra...@gmx.de wrote:

> The real thing:
> The usbstick has a partition table, which was the reason to ask
> for a way to preserve it.

OK, I wasn't sure if it did.

In this case as I suggested, fdisk will show you the number and size of 
partitions.  minfo will show you the geometry of the partition, should you 
wish to manually recreate it in the future.  However, there are tools to help 
avoid manual partitioning!  ;-)

To answer exactly what you asked, copy the partition table (assuming all the 
USB stick contains is a single primary partition) by using good ol' dd:

dd if=/dev/sdX of=~/mbr.img bs=512 count=1


Reverse the command to paste the MBR and partition table back.  That should 
bring you back where you started when you first bought the USB stick.  If for 
some weird reason the USB stick partitioning scheme included extended and 
logical partitions, then read one additional step below. 


> Again my questions:
> Where are the partioning/format defining on the device?
> If there are only stored the beginning of the device: How
> much do I need to copy?
> If there are tools to extract all needed informations of the
> partioning/formatting and to recreate exactly that kind of
> partitioning/formatting later with that or other tools:
> Which tools do I need and how to use them?

First copy the MBR and partition table using dd as I suggested above.  Then 
use sfdisk --dump to create a text file with information on the size and 
positioning of the remaining partitions.

sfdisk --dump /dev/sdX > sdX.dump


To restore first run dd in the reverse order:

dd if=~/mbr.img of=/dev/sdX bs=512 count=1

Then change the file director on the sfdisk --dump command:

sfdisk --dump /dev/sdX < sdX.dump

Needless to say you will need both 'mbr.img' and 'sdX.dump' files to restore 
the drive partitioning scheme to its original state, if it contains more than 
one primary partition.  When you are restoring the partition tables, double 
check the /dev/sdX name or you could damage some other disk in your system!

-- 
Regards,
Mick

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