Re: Cloning a disk using dd

On Wed, 31 Oct 2007 19:44:41 -0500, General Schvantzkopf wrote:

I'm trying to clone a Win2K disk using Fedora Live on a USB FLASH disk. I
did a

dd if=/dev/sda of=/dev/sdb

It seems to have cloned the MBR correctly and the partition layout looks
correct when I look at it using GParted. However when I tried to the boot
the cloned 2K disk it started to boot and then failed with an
inaccessible boot disk error. When I booted the original 2K disk and
tried to look at the cloned disk it said that the disk wasn't formatted.
So it appears that the NTFS file system wasn't cloned correctly.

The source disk is an old 40G that I had laying around, the destination
disk is a new 500G. After the dd there was a 40G partition on the 500G
disk and dd reported that it copied the right number of bytes.

Is there a switch to dd that I need to add to the command? Does anyone
have any idea about what went wrong?

The partition table uses (cylinders, heads, sectors). If the two drives
have a different number of (heads,sectors), then I don't think strict "dd"
will work. The drives have to be almost identical to work, especially with
Windows in the mix. However, if the OS is only GNU/Linux, then it might
work because LBA disk mode is always used- even by the loader.

--
Douglas Mayne

.

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