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Fabby
Asked: 2017-09-21 12:36:42 +0800 CST

How do I take a backup of my Master Boot Record (MBR) and Partition Table (PT)?

  • 772

I'd like to know how to:

  1. take a backup
  2. do a restore

of all the MBRs and all the PTs of all my disks to a file so I can easily back them up using rsync or a comparable program.

partitioning

2 Answers

  1. Best Answer

    Hah, that's pretty easy:

    1. create a directory /sysbackup:

      mkdir /sysbackup

    2. copy the following script in an editor:

      #!/bin/bash
#
# This script saves the well-known (last good) partition table entries to a text file 
# and the MBR to a binary file for all live disks on the system.
#
# Copyright (c) Fabby 2017
#
# This program is free software: you can redistribute it and/or modify it under 
# the terms of the GNU General Public License as published by the Free Software 
# Foundation, either version 3 of the License, or (at your option) any later 
# version.
#
# This program is distributed in the hope that it will be useful, 
# but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
# or FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
# DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
# THE USE OR OTHER DEALINGS IN THE SOFTWARE. 
# See the GNU General Public License for more details.
#
# You DID NOT receive a copy of the GNU General Public License along with 
# this program as the license is bigger then this program.
# Therefore, see http://www.gnu.org/licenses/ for more details.
#
# This script should be run at the /etc/rc.local or systemd equivalent point in time
#
for szDisk in /dev/?d?; 
do
  sfdisk --dump "$szDisk" > /sysbackup/PartBackup-"$(hostname)-${szDisk//\//-}""$(date +"%F-%H%M%S%N")"".txt"
  dd if="$szDisk" of=/sysbackup/MBRBackup-"$(hostname)-${szDisk//\//-}""$(date +"%F-%H%M%S%N")"".bck" bs=512 count=1
done;

    3. save it in /usr/local/bin (E.g. as mbr-pt-bck)

    4. chmod +x /usr/local/bin/mbr-pt-bck
    5. execute it using sudo mbr-pt-bck
    6. Ensure /sysbackup/ is included in your rsync (or comparable) command.

    Alternatively,

    • put the above script in /etc/rc.local or equivalent systemd and auto-execute it at every boot.
    • include it in your pre-backup script
    • 4

  2. To restore any of the above is pretty easy too:

    MBR:

    dd if=/sysbackup/MBRBackup-szHostName-dev-sda.bck of=/dev/sda  bs=512 count=1

    PT:

    First to a cat /sysbackup/PartBackup-szHostName-dev-sda.txt

    Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031   8056.032  primary   ext3

    Then just do a:

    parted /dev/sda rescue

    and you'll get the parted rescue prompt, where you fill in the data from the above cat

    Start? 0
End? 8056
Information: A ext3 primary partition was found at 0.031MB ->
8056.030MB.  Do you want to add it to the partition table?
Yes/No/Cancel? y
    • 0