How to clone hard drive or partition in Linux

Cloning a disk or partition in Linux is essential for data backup, system migration, and forensic analysis. It allows you to create an exact copy of a disk or partition, preserving all data, including the boot sector and partition table. This ensures that the original system remains unchanged while the clone can be used for testing, recovery, or analysis.

There are several tools available in Linux for disk cloning, such as Partimage, Partclone, Clonezilla, and dd. Among these, dd is widely used because it is simple, comes pre-installed on most Linux distributions, and operates at a block level. This means it copies the disk or partition bit by bit, ensuring an accurate replica essential for system recovery or migration.

Before cloning, ensure that the source disk or partition is unmounted and not in use to avoid data corruption. Verify that the target disk or partition has enough space to accommodate the source. Using dd, you can easily clone a disk or partition with minimal effort, making it a reliable choice for Linux users.

1. Open the terminal.
2. Identify the source disk or partition to clone.

   $ lsblk
   NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
   loop0    7:0    0 88.5M  1 loop /snap/core/7270
   loop1    7:1    0 54.1M  1 loop /snap/lxd/10972
   loop2    7:2    0 89.4M  1 loop /snap/core/6818
   loop3    7:3    0 54.1M  1 loop /snap/lxd/11098
   loop4    7:4    0 89.3M  1 loop /snap/core/6673
   sda      8:0    0   20G  0 disk
   ├─sda1   8:1    0    1M  0 part
   └─sda2   8:2    0   20G  0 part /
   sdb      8:16   0    5G  0 disk
   └─sdb1   8:17   0    5G  0 part /mnt/data
   sr0     11:0    1  748M  0 rom

   For this example, we're going to clone the sdb1 partition to an image file.

3. Examine the source disk and partition information.

   From the above lsblk output, sdb1 is a 5GB partition mounted on /mnt/data.

4. Unmount the source disk or partition.

   $ sudo umount --force /dev/sdb1

5. Verify that the target disk or partition has enough space.

   $ df -h /dev/sda2
   Filesystem      Size  Used Avail Use% Mounted on
   /dev/sda2        20G  5.2G   14G  28% /

   Target disk drive or partition needs to have at least the same capacity, and mounted partition for the target file needs to have enough free disk space. In this case, our target mounted partition still have 14GB available for the required 5GB.

6. Use dd to clone the source to the target.

   $ sudo dd if=/dev/sdb1 of=/root/sdb1-backup.img conv=noerror,sync status=progress
   [sudo] password for user:
   5347731456 bytes (5.3 GB, 5.0 GiB) copied, 49 s, 109 MB/s
   10483712+0 records in
   10483712+0 records out
   5367660544 bytes (5.4 GB, 5.0 GiB) copied, 49.2271 s, 109 MB/s

   Cloning an entire disk will also clone the master boot record and partition table

7. Verify the cloned disk or partition.

   $ sudo file /root/sdb1-backup.img
   /root/sdb1-backup.img: Linux rev 1.0 ext4 filesystem data, UUID=d430e0a1-ec3e-4bed-b16a-e2d35d0f4ed6 (extents) (64bit) (large files) (huge files)