[sf-lug] use dd to copy the mbr

[jim stockford]

from
http://searchenterpriselinux.techtarget.com/tip/ 
0,289483,sid39_gci1244256,00.html

# dd if=/boot/mbr_backup of=/dev/sda bs=446 count=1
# # their example above

# # or, copy from the primary master to primary slave:
# dd if=/dev/hda of=/dev/hdb bs=446 count=1

note the bs=446 rather than bs=512 lets you copy the
bootstrap loader code without copying the partition table
(if you use bs=512 you copy the partition table from the
source and overwrite that of the target).