Which Linux distributions do you use?

[flameout]

Originally Posted by Ether

dd if=/dev/sda of=/mnt/sdb1/MBR.img bs=512 count=1

Just to be 100% clear:

For the reasons explained by rbmj above, this command is perfectly safe.

The output file, /mnt/sdb1/MBR.img is a normal file -- it is not a device node, and does not control anything inside the kernel. Therefore, writing to it is a safe operation.

The underlying filesystem is sufficiently abstracted away such that dd is never aware it is writing to an NTFS partition -- it simply tells the kernel "put this data into this file", and the kernel deals with the filesystem itself.