Installation guide

24 Chapter 2. Hardware Installation and Operating System Configuration
The following is an example of an /etc/hosts file on a node of a cluster that does not
use DNS-assigned hostnames:
127.0.0.1 localhost.localdomain localhost
192.168.1.81 node1.example.com node1
193.186.1.82 node2.example.com node2
193.186.1.83 node3.example.com node3
The previous example shows the IP addresses and hostnames for three nodes (node1,
node2, and node3),
Important
Do not assign the node hostname to the localhost (127.0.0.1) address, as this causes
issues with the CMAN cluster management system.
Verify correct formatting of the local host entry in the /etc/hosts file to ensure that
it does not include non-local systems in the entry for the local host. An example of an
incorrect local host entry that includes a non-local system (server1) is shown next:
127.0.0.1 localhost.localdomain localhost server1
An Ethernet connection may not operate properly if the format of the /etc/hosts file is
not correct. Check the /etc/hosts file and correct the file format by removing non-local
systems from the local host entry, if necessary.
Note that each network adapter must be configured with the appropriate IP address and
netmask.
The following example shows a portion of the output from the /sbin/ip addr list
command on a cluster node:
2: eth0: <BROADCAST,MULTICAST,UP> mtu 1356 qdisc pfifo_fast qlen 1000
link/ether 00:05:5d:9a:d8:91 brd ff:ff:ff:ff:ff:ff
inet 10.11.4.31/22 brd 10.11.7.255 scope global eth0
inet6 fe80::205:5dff:fe9a:d891/64 scope link
valid_lft forever preferred_lft forever
You may also add the IP addresses for the cluster nodes to your DNS server. Refer to the
Red Hat Enterprise Linux System Administration Guide for information on configuring
DNS, or consult your network administrator.