Master boot record (MBR) — code and data located in the first 512 bytes of the hard disk needed to boot the operating system.
From 512 bytes of MBR code contains:
446 bytes — Bootstrap
64 bytes — Partition table
2 bytes — Signature
Backup MBR:
dd if=/dev/sda of=/dir/sda.mbr bs=512 count=1
Options:
if – source
of – file or destination device
bs – the number of bytes to be read at a time
count – the number of times a record
Check whether the file was created:
file /dir/sda.mbr
To restore the MBR run the command:
dd if=/dir/sda.mbr of=/dev/sda bs=512 count=1
You can also use the sfdisk utility.
Creating a copy of the partition table:
sfdisk -d /dev/sda > /dir/sda.sfdisk
Restore partition table:
sfdisk /dev/sda < /dir/sda.sfdisk