dd MBR . dd ( ) . MBR fail-over hard-disk RAID-1, hard-disks. .

hdb
dd if=/dev/had of=/dev/hdb bs=512 count=1

BTW: MBR RAID-1. hard-disk RAID-1, hard-disk . . /proc/mdstat hard-disk .


dd if=/dev/had bs=512 count=1 > had_backup

had_backup MBR .

had_backup
if=had_backup of=/dev/had bs=512 count=1 dd

: hdb . , hdb sda, sdb etc. .