Configure the Private and Public Networks

On the master node, execute ip addr to view the available Ethernet devices. These are typically named eth0 and eth1, although the names may vary for your master node. The controller that is connected to the private cluster network must have a static IP address and be able to communicate with all the compute nodes, which themselves will be assigned a dynamic IP address when booting. The controller that is connected to the public cluster network can have a dynamic IP address or a static IP address, although the latter is preferable for consistency in accessing the master node from some other machine in the public network space.

Edit the /etc/beowulf/config configuration file to specify the private network interface details. Find the “interface” directive, and change the initially undefined “none” name to the actual interface name, and change the “iprange” directive to be the base address of the first compute node, which is typically node n0. Then change the “nodes” directive to specify the maximum number of compute nodes that are connected to the private cluster network.

For example, suppose the interface name is “eth1”, the master node’s IP address is 10.20.0.1, and there are currently eight compute nodes connected, with a plan to add an additional eight later. The config file may then specify:

interface eth1
nodes 16
iprange 10.20.0.4

Note that the above “iprange” allows room for three additional master nodes, if desired, each with an unique IP address in the range 10.20.0.0 to 10.20.0.3. The 16 compute nodes span 10.20.0.4 to 10.20.0.19.