Step 2. Prepare for the installation

The following prerequisites must be met for the installation:

• Make sure that the nodes and NFS server for the installation meet the minimum system requirements. For details, see Step 1. Meet the system requirements.

• The master node and the worker nodes must have a static IP address.

• The host names of the master and the worker nodes must be DNS resolvable (not only via /etc/hosts).

• Use the root user for the installation.

• If the machine already has Docker or Kubernetes installed, uninstall them.

• Disable your existing firewall on all nodes by running the following commands:

  systemctl stop firewalld
systemctl disable firewalld

  The firewall has to stay disabled also after the installation.

• The following ports are needed on all nodes during and after the installation, and should not be used by another application: 2380, 4001, 4194, 5000, 5443, 8080, 8200, 8443, 10250, 10251, 10252, 10255, 31387, 31389.

  The following ports must be open for system processes: 111 (rpcbind), 2049 (NFS), 20048 (rpc.mountd).

  Note The installation script checks and reports if necessary ports are in use.

• Check if you have installed the following rpm packages on all nodes:

  rpm -qa | grep -E "java-1.8.0-openjdk|libgcrypt|libseccomp|libtool-ltdl|net-tools|nfs-utils|systemd-libs|device-mapper-libs|lsof|unzip|chrony|rpcbind"

  Note Java is only required on the master node. systemd-libs must be version 219 or higher.

  If one or multiple of the packages are not installed, install them using yum install:

  yum install java-1.8.0-openjdk libgcrypt libseccomp libtool-ltdl net-tools nfs-utils systemd-libs device-mapper-libs lsof unzip chrony rpcbind

  If you installed Chrony, run the following commands afterwards:

  systemctl start chronyd
systemctl enable chronyd

• Remove the shared NFS folder if you have previously installed the ITOM Platform. The default folder is /var/vols/itom/core.
  For example: rm -rf /var/vols/itom/core/*

  Also remove the directory on the NFS server where you stored Operations Bridge suite data, if you previously installed the Operations Bridge Suite, for example:

  rm -rf /var/vols/itom/opsbridge/*

• The NFS server, the master node, and the worker nodes should be installed under the same subnet.

• Make sure that the browser cache is cleared.

• The time on the master and all worker nodes should be the same. To synchronize the time on your nodes, you can, for example, use NTP or VMWare tools.

• Make sure that https_proxy and http_proxy settings are not set (unset https_proxy; unset http_proxy). Alternatively, add the IP address of the master node to the no_proxy list for the master and all worker nodes.

  Example: set no_proxy="localhost,127.0.0.1,<master_node_IP>"

  Make sure that these settings are consistent on all nodes.