Cloning Arch Linux hard disk remotely to new machine

I recently bought a new laptop with Windows 11 and wanted to migrate my whole hard drive contents from my old laptop with an Arch Linux installation.

Follow this tutorial if you want to clone your old laptop’s hard drive to your new laptop’s hard drive via SSH in the same local network.

Table of Contents

Boot from Live USB

In our new machine we will run all commands from a live USB Arch Linux image.

Follow the official Arch Linux tutorial to boot an Arch Linux image from an USB.

Once you have your live USB, plug it in your new laptop and go to the boot menu.

In my case, I have a Thinkpad and I had to press enter and then F12 when powering on the laptop.

I also had to disable Secure Boot beforehand to boot from my live USB.

Make sure to connect to the same local wifi network in both machines before continuing.

Setup SSH

The following commands are executed as root user.

Run su on your old machine to become root user.

Check IP address of new machine with ip address:

root@archiso ~ # ip address

    <...>

4: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether a0:59:50:e1:5f:9b brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.76/24 metric 600 brd 192.168.1.255 scope global dynamic wlan0
       valid_lft 39244sec preferred_lft 39244sec
    inet6 fe80::a259:50ff:fee1:5f9b/64 scope link
       valid_lft forever preferred_lft forever

Our local ip in this example is 192.168.1.76.

Start ssh service in new machine:
```
systemctl start sshd.service
```
Set the root password with passwd. Simply run passwd in your new machine.

Now we setup ssh so it doesn’t ask for password when connecting to our new machine. In your old machine:

ssh-keygen -t ed25519
ssh-copy-id -i .ssh/id_thinkpadp15.pub root@192.168.1.76

In my case it looks like:

[root@thinkpad-t440s ~]$ ssh-keygen -t ed25519
Generating public/private ed25519 key pair.
Enter file in which to save the key (/home/saheru/.ssh/id_ed25519): .ssh/id_thinkpadp15
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in .ssh/id_thinkpadp15
Your public key has been saved in .ssh/id_thinkpadp15.pub
The key fingerprint is:
SHA256:DJ74VMCmqQ6nB//xZkPhSmPZRR00lVqskcZ2TH5N5wc saheru@thinkpad-t440s
The key's randomart image is:
+--[ED25519 256]--+
|     ..  ++Bo.E o|
|      o.. Bo*  =.|
|     +...o *. . +|
|    oo.=. o  .  .|
|   ..++oS        |
|o o =o+          |
| B o.+.          |
|. + .o+          |
| . ..o..         |
+----[SHA256]-----+
[root@thinkpad-t440s ~]$ ssh-copy-id -i .ssh/id_thinkpadp15.pub root@192.168.1.76

Note that I named my key .ssh/id_thinkpadp15.

The last command will ask for the root password, which is the one we have set in the previous step.

Append your new machine’s IP with the corresponding private key in your old machine’s .ssh/config (create the file if it doesn’t exist), in my case:
```
Host 192.168.1.76
  HostName 192.168.1.76
  User root
  IdentityFile ~/.ssh/id_thinkpadp15
```
Now ssh won’t prompt for a password when we connect to our new machine.

Clone hard disk via SSH

We will use the dd command from coreutils and ssh to remotely clone our hard disk from our old machine to our new machine.

Check the official Arch wiki for more info on cloning with dd.

The following commands completely erase the new machine’s hard disk contents! Make sure to save a backup image.

First, make sure you have enough space in your new hard disk. You can check this by running lsblk on your old and new machines.

Also make sure your hard disk in your new machine is unmounted with lsblk (MOUNTPOINTS should be empty).

In my case the hard disk in my new machine was nvme0n1. Make sure you choose the correct disk by looking at SIZE in lsblk.

To avoid corrupting files during cloning, you should run the following command from another live USB in your old machine and make sure your hard drive sda is unmounted.

Run the following in your old machine to clone the disk:

dd if=/dev/sda | ssh root@192.168.1.76 dd of=/dev/nvme0n1 status=progress

Change the IP, and sda and nvme0n1 according to your source and destination disk names.

It will take 5-10h to clone a 512GB SSD. Once it finishes, you will have copied all the contents from your old machine to your new machine, including GRUB and LUKS (also with logical volumes) if you had them setup.