RHEL: Back-up/Replicate a partition table

# Tested on RHEL 5, 6 & 7

# Given the importance of disk's partition table, one should consider to make a backup
# in a regular basis in order to be able to restore it in case it will get corrupted,
# modified or deleted by mistake.

# We may still have the data unchanged on the disk but without a correct partition table
# it may be almost impossible to recover it.

# To get a disk's table partition we can use the 'fdisk -l' command:

fdisk -l /dev/sda

   Disk /dev/sda: 32.2 GB, 32212254720 bytes
   255 heads, 63 sectors/track, 3916 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes

      Device Boot      Start         End      Blocks   Id  System
   /dev/sda1   *           1          33      265041   83  Linux
   /dev/sda2              34        1958    15462562+  8e  Linux LVM
   /dev/sda3            1959        2088     1044225   8e  Linux LVM
   /dev/sda4            2089        2349     2096482+   5  Extended
   /dev/sda5            2089        2349     2096451   83  Linux

# This output may be stored in a text file. Then we could use this information to
# recreate partitions manually.

# Apart from this method we may use 'sfdisk' command to inject partition table to
# a disk:
# First we get disk's partition table to a text file (-d for "dump"):

sfdisk -d /dev/sda
   # partition table of /dev/sda
   unit: sectors

   /dev/sda1 : start=       63, size=   530082, Id=83
   /dev/sda2 : start=   530145, size= 30925125, Id=8e
   /dev/sda3 : start= 31455270, size=  2088450, Id=8e
   /dev/sda4 : start= 33543720, size=  4192965, Id= 5
   /dev/sda5 : start= 33543783, size=  4192902, Id=83

sfdisk -d /dev/sda > sda_partition_table

# and then, when needed, we could restore the partition table to the disk:

sfdisk /dev/sda < sda_partition_table

# Force option, '-f', may be useful in certain cases where a normal update is not possible

# Tip:  We can use 'sfdisk' to replicate a partition table from a disk to another disk with
# the same geometry:

sfdisk -d /dev/sda | sfdisk [-f] /dev/sdb
0 (0)
Article Rating (No Votes)
Rate this article
There are no attachments for this article.
There are no comments for this article. Be the first to post a comment.
Full Name
Email Address
Security Code Security Code
Related Articles RSS Feed
How to accurately determine when the system was booted
Viewed 1099 times since Wed, Oct 3, 2018
Tip: SSD and Linux. Enable TRIM and check if it works
Viewed 1685 times since Fri, May 15, 2020
LUKS List available methods of encryption for LUKS
Viewed 1014 times since Fri, Jul 13, 2018
Top 4 Reasons for Node Reboot or Node Eviction in Real Application Cluster (RAC) Environment
Viewed 17108 times since Thu, Jun 21, 2018
Jak ustawić LVM, jak robić snapshoty oraz automatycznie powiększać LV, czyli małe howto
Viewed 2835 times since Sun, May 20, 2018
python learning
Viewed 807 times since Wed, Dec 18, 2019
RHCS6: Extend an existing Logical Volume / GFS2 filesystem
Viewed 1643 times since Sun, Jun 3, 2018
18 Quick ‘lsof’ command examples for Linux Geeks
Viewed 8493 times since Sun, Jun 30, 2019
Top 25 Best Linux Performance Monitoring and Debugging Tools
Viewed 4121 times since Sun, Sep 30, 2018
OpenSSL – sprawdzanie czy klucz pasuje do certyfikatu
Viewed 1517 times since Thu, May 24, 2018