Linux backup mbr

Backup MBR and Extended Partitions :

# dd if=/dev/sdc of=/tmp/backup-sdc.mbr bs=512 count=1

# sfdisk -d /dev/sdc > /tmp/backup-sdc.sfdisk

Restore MBR and Extended Partitions :

# dd if=backup-sdc.mbr of=/dev/sdc

# sfdisk /dev/sdc < backup-sdc.sfdisk 

References :
UNIX / Linux: Copy Master Boot Record (MBR)