Linux clone disk

Using dd (device dump) to clone/copy the entire disk

Disk to Disk

• Source: /dev/sda (not mounted), size=4GB
• Target: /dev/sdb (not mounted), size=8GB
• View source details

root@raspberrypi:~ # fdisk -l /dev/sda
Disk /dev/sda: 3.75 GiB, 4026531840 bytes, 7864320 sectors
Disk model: STORAGE DEVICE
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x4808f986

Device     Boot  Start     End Sectors  Size Id Type
/dev/sda1         8192  532479  524288  256M  c W95 FAT32 (LBA)
/dev/sda2       532480 7864286 7331807  3.5G 83 Linux

• Copy /dev/sda/ to /dev/sdb

root@raspberrypi:~ # dd if=/dev/sda of=/dev/sdb
7864320+0 records in
7864320+0 records out
4026531840 bytes (4.0 GB, 3.8 GiB) copied, 1118.79 s, 3.6 MB/s

• Compare the result

root@raspberrypi:~ # fdisk -l /dev/sdb
Disk /dev/sdb: 7.4 GiB, 7948206080 bytes, 15523840 sectors
Disk model: STORAGE DEVICE
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x4808f986

Device     Boot  Start     End Sectors  Size Id Type
/dev/sdb1         8192  532479  524288  256M  c W95 FAT32 (LBA)
/dev/sdb2       532480 7864286 7331807  3.5G 83 Linux

Disk to Image

• Source: /dev/sda (not mounted), size=4GB
• Target: /dev/sdb (mounted), size=8GB
• View source details

root@raspberrypi:~ # fdisk -l /dev/sda
Disk /dev/sda: 3.75 GiB, 4026531840 bytes, 7864320 sectors
Disk model: STORAGE DEVICE
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x4808f986

Device     Boot  Start     End Sectors  Size Id Type
/dev/sda1         8192  532479  524288  256M  c W95 FAT32 (LBA)
/dev/sda2       532480 7864286 7331807  3.5G 83 Linux

• Create and mount the filesystem

root@raspberrypi:~ # mkfs.vfat /dev/sdb1
mkfs.fat 4.2 (2021-01-31)

root@raspberrypi:~ # mount/dev/sdb /mnt

root@raspberrypi:~ # df -h | grep mnt
/dev/sdb1       7.4G  4.0K  7.4G   1% /mnt

• Clone to Image

root@raspberrypi:~ # dd if=/dev/sda of=/mnt/clonetest.iso
7864320+0 records in
7864320+0 records out
4026531840 bytes (4.0 GB, 3.8 GiB) copied, 432.071 s, 9.3 MB/s

• View the result

root@raspberrypi:~ # ls /mnt -allh
total 3.8G
drwxr-xr-x  2 root root 4.0K Jan  1  1970 .
drwxr-xr-x 19 root root 4.0K Mar 12 18:55 ..
-rwxr-xr-x  1 root root 3.8G May 28 20:30 clonetest.iso

Disk to Network/Image

• Source: /dev/sda (not mounted), size=4GB
• Target: sshfs /dev/mnt (mounted)
• View source details

root@raspberrypi:~ # fdisk -l /dev/sda
Disk /dev/sda: 3.75 GiB, 4026531840 bytes, 7864320 sectors
Disk model: STORAGE DEVICE
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x4808f986

Device     Boot  Start     End Sectors  Size Id Type
/dev/sda1         8192  532479  524288  256M  c W95 FAT32 (LBA)
/dev/sda2       532480 7864286 7331807  3.5G 83 Linux

• Prepare SSH Filesystem

root@raspberrypi:~ # apt-get install sshfs

• Mount filesystem

root@raspberrypi:~ # sshfs -o allow_other,default_permissions vmadmin@192.168.178.67:/ /mnt
vmadmin@192.168.178.67's password:

• Clone the running OS Disk

root@raspberrypi:~ # dd if=/dev/mmcblk0 of=/mnt/data/clonetest.iso
3901440+0 records in
3901440+0 records out
1997537280 bytes (2.0 GB, 1.9 GiB) copied, 278.75 s, 7.2 MB/s