🐧Linux - LAN Cluster

Premise

In this guide we'll create the simplest slave/master server configuration, using only Linux devices.

You can use any suitable machine for the master; we'll use a generic HP Pavilion 15 laptop with two ethernet ports.

I'm using a generic HP 250 G6 Notebook and an E402MA (ASUS-NotebookSKU), as slaves, both of which are laptops.

Link each slave to the master with an ethernet cable.

It's worth mentioning that a PC is not meant to be used as a server;
bad performance/energy consumption.

Requirements

• 1 Linux Device with at least 2 ethernet ports
• 1 or more linux devices (slave) with at least 1 ethernet port each
• 1 ethernet cable for each slave
• DHCPCD client installed in each device

Slave

Install DHCPCD:
$ apt install dhcpcd5

Edit edit the configuration file of DHCPCD, usually /etc/dhcpcd.conf, and give a static IP to the ethernet interface of each slave, in my case the interface name is eno1, you can refer to the following lines:

(HP 250 G6 Notebook)
interface eno1
static ip_address=10.0.99.2

[E402MA (ASUS-NotebookSKU)]
interface eno1
static ip_address=10.0.98.2

And so on.

Master

Userspace /dev

It's worth creating a new rule set for udev; make a new file, we'll call it 60-homecluster.rules:
$ touch /etc/udev/rules.d/60-homecluster.rules

For each slave server, use ifconfig or cat /sys/class/net/${INTERFACE}/address to retrieve the interface MAC address. For example:

$ cat /sys/class/net/eno1/address

In our example, the master has two ethernet interfaces, eth1 and eth2.
Map each device MAC with an interface.
Remember to replace DEVICE_MAC with the MAC address you retrieved.

For the HP 250 G6 Notebook
SUBSYSTEM=="net", ATTR{address}=="DEVICE_MAC", NAME="eth1"

For the E402MA (ASUS-NotebookSKU)
SUBSYSTEM=="net", ATTR{address}=="DEVICE_MAC", NAME="eth2"

And so on.

60-homecluster.rules should look like this

SUBSYSTEM=="net", ATTR{address}=="f4:30:b9:52:55:78", NAME="eth1"
SUBSYSTEM=="net", ATTR{address}=="10:f0:05:ce:87:28", NAME="eth2"

DHCP

Edit the configuration file of DHCPCD, usually /etc/dhcpcd.conf, and give each slave a local IP block

interface eth1
static ip_address=10.0.99.1/24

interface eth2
static ip_address=10.0.98.1/24

Finally, make sure you connected each ethernet cable; restart DHCPCD
$ dhcpcd -k

Wait at least a couple of seconds:
$ dhcpcd

Try connect with SSH
$ ssh username@10.0.99.2
$ ssh username@10.0.98.2