10.2. Cluster Does Not Form
If you find you are having trouble getting a new cluster to form, check for the following things:
- Make sure you have name resolution set up correctly. The cluster node name in the
cluster.conffile should correspond to the name used to resolve that cluster's address over the network that cluster will be using to communicate. For example, if your cluster's node names are
nodebmake sure both nodes have entries in the
/etc/hostsfile that match those names.
- If the cluster uses multicast for communication between nodes, make sure that multicast traffic is not being blocked, delayed, or otherwise interfered with on the network that the cluster is using to communicate. Note that some Cisco switches have features that may cause delays in multicast traffic.
SSHto verify whether you can reach remote nodes.
- Execute the
ethtool eth1 | grep linkcommand to check whether the ethernet link is up.
- Use the
tcpdumpcommand at each node to check the network traffic.
- Ensure that you do not have firewall rules blocking communication between your nodes.
- Ensure that the interfaces the cluster uses for inter-node communication are not using any bonding mode other than 0, 1, or 2. (Bonding modes 0 and 2 are supported as of Red Hat Enterprise Linux 6.4.)