ha-cluster-join fails on syncing configuration files

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Environment

SUSE Linux Enterprise High Availability Extension 12
SUSE Linux Enterprise High Availability Extension 11 Service Pack 4
SUSE Linux Enterprise High Availability Extension 11 Service Pack 3
SUSE Linux Enterprise High Availability Extension 11 Service Pack 2

Situation

Building a new Pacemaker cluster with ha-cluster-init/sleha-init succeeds to set up the first node, however adding a new node with ha-cluster-join/sleha-join fails with a csync2 error:

n2:~ # ha-cluster-join

[...]

  IP address or hostname of existing node (e.g.: 192.168.1.1) [] 10.10.1.10

[...]

WARNING: csync2 run failed - some files may not be sync'd

  Merging known_hosts

WARNING: known_hosts collection may be incomplete

WARNING: known_hosts merge may be incomplete

  Probing for new partitions......done

ERROR: /etc/corosync/corosync.conf is not readable. Please ensure that hostnames are resolvable.

Resolution

To resolve this error either add the hostname of the nodes to your DNS server or add them into /etc/hosts on both/all nodes as follows:

cat /etc/hosts

10.10.1.10    n1.example.com    n1

10.10.1.11    n2.example.com    n2

and then re-run the ha-cluster-join script.

Cause

The ha-cluster-join script uses the csync2 tool to sync configuration files across the nodes which uses hostnames instead of IP
addresses:

n1:~ # cat /etc/csync2/csync2.cfg

group ha_group

    key /etc/csync2/key_hagroup;

    host n2;

    host n1;

    include /etc/booth;

    include /etc/corosync/corosync.conf;

    include /etc/corosync/authkey;

    include /etc/csync2/csync2.cfg;

    include /etc/csync2/key_hagroup;

    include /etc/ctdb/nodes;

    include /etc/drbd.conf;

    include /etc/drbd.d;

    include /etc/ha.d/ldirectord.cf;

    include /etc/lvm/lvm.conf;

    include /etc/multipath.conf;

    include /etc/samba/smb.conf;

    include /etc/sysconfig/pacemaker;

    include /etc/sysconfig/sbd;

Because it can not resolve hostnames, it fails to sync the cluster configuration files which in turn then leads to the error when
Pacemaker attempts to start corosync.

Disclaimer

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