Preparation to install Omnia

Assumptions

Ensure that the following prerequisites are met:

The manager and compute nodes must be running CentOS 7.9 2009 OS.
All nodes are connected to the network and have access to Internet.
SSH Keys for root have been installed on all nodes to allow for password-less SSH.
On the manager node, install Ansible and Git using the following commands:
- yum install epel-release -y
- yum install ansible-2.9.18 git -y
  Note: Ansible must be installed using yum. If Ansible is installed using pip3, re-install it using the yum command again.

Omnia can configure systems which use Ethernet or Infiniband-based fabric to connect the compute servers.

Omnia assumes that servers are already connected to the network and have access to the internet.

Possible network configurations include:

A flat topology where all nodes are connected to a switch which includes an uplink to the internet. This requires multiple externally-facing IP addresses
A hierarchical topology where compute nodes are connected to a common switch, but the manager node contains a second network connection which is connected to the internet. All outbound/inbound traffic would be routed through the manager node. This requires setting up firewall rules for IP masquerade, see here for an example.

IP and Hostname Assignment

The recommended setup is to assign IP addresses to individual servers. This can be done manually by logging onto each node, or via DHCP.