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
10 Linux cryptsetup Examples for LUKS Key Management (How to Add, Remove, Change, Reset LUKS encryption Key)
Viewed 1158 times since Tue, Jul 31, 2018
List DNS records, nameservers of a domain from command line
Viewed 571 times since Sun, Sep 30, 2018
Modifying the inode count for an ext2/ext3/ext4 file system
Viewed 90 times since Fri, Sep 18, 2020
RHEL: Bonding network interfaces
Viewed 1163 times since Sat, Jun 2, 2018
HowTo: Create CSR using OpenSSL Without Prompt (Non-Interactive)
Viewed 956 times since Mon, Feb 18, 2019
An easier way to manage disk decryption at boot with Red Hat Enterprise Linux 7.5 using NBDE
Viewed 2083 times since Mon, Aug 6, 2018
logrotate - rotates, compresses, and mails system logs.
Viewed 549 times since Fri, Nov 30, 2018
Odpalenie polecenia tylko na jedną godzinę
Viewed 958 times since Thu, May 24, 2018
RHEL: Scan and configure new SAN (fibre channel) LUNs
Viewed 1371 times since Sun, May 27, 2018
Używanie rsync poprzez Secure Shell
Viewed 37189 times since Thu, May 24, 2018