All machines (cluster nodes and arbitrators) that will be part of the Geo cluster have the following software installed:
SUSE® Linux Enterprise Server 12 SP5
SUSE Linux Enterprise High Availability Extension 12 SP5
Geo Clustering for SUSE Linux Enterprise High Availability Extension 12 SP5
The virtual IPs to be used for each cluster site must be accessible across the Geo cluster.
The sites must be reachable on one UDP and TCP port per booth instance. That means any firewalls or IPsec tunnels in between must be configured accordingly.
Other setup decisions may require to open more ports (for example, for DRBD or database replication).
All cluster nodes on all sites should synchronize to an NTP server outside the cluster. For more information, see https://documentation.suse.com/sles-12/html/SLES-all/cha-netz-xntp.html.
If nodes are not synchronized, log files and cluster reports are very hard to analyze.
Use an uneven number of members in your Geo cluster. In case the network connection breaks down, this makes sure that there still is a majority of sites (to avoid a split brain scenario). In case you have an even number of cluster sites, use an arbitrator.
The cluster on each site has a meaningful name, for example:
amsterdam
and berlin
.
The cluster names for each site are defined in the respective
/etc/corosync/corosync.conf
files:
totem { [...] cluster_name: amsterdam }
This can either be done manually (by editing /etc/corosync/corosync.conf
) or with the
YaST cluster module (by switching to the category and defining a ). Afterward, stop and start the pacemaker
service for the changes to take effect:
root #
systemctl
stop pacemakerroot #
systemctl
start pacemaker