On 14 Jul 2010, at 11:37, Phil Thompson wrote: > A question arising from my Hackintosh efforts..... > > If using dd to copy an image to a device - say an img file to a USB stick - > does the transfer occur at the lowest level or is the image written to the > partition / format structure that exists. > > My expectation was that if I dd an img file to /dev/sdc (a USB stick) that it > would end up with the partitioning, MBR and file structure as defined in the > img file ? >
I would not have thought so: The partition table is not part of the MBR (I belive) > If that is the case, why do I see tutorials that go on at length about > formatting sticks and using the right file system / partition table type, > only to then splat an image on them with dd ? Because if as above the partition table is not part of the MBR then the dd image will not have the partition information. So lets say one has a 4GB USB stick and a 500 GB HDD and did a dd image of the USB stick and dd that image to the disk the best one could hop for is 4GB used space and 496GB unused and un-accessable space. But because of the difences not only between HDD to HDD and HDD to USB stick (Physichall platers, heads and the logical tracks, cylinders, sectors and such) to most likeley out come is that the information on the HDD would be carbage as all of the pointers to information would be pointing to the wrong places. > > For clarity I'm taling about a simple dd command like > > dd if=stick.img of=/dev/sdc > > without any qualifying parameters This is often who commands are not normaly that simple. > > > Phil > Steve > _______________________________________________ > Peterboro mailing list > Peterboro@mailman.lug.org.uk > https://mailman.lug.org.uk/mailman/listinfo/peterboro > _______________________________________________ Peterboro mailing list Peterboro@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/peterboro
