This chapter describes configuring one active node and one standby node in a cluster environment. In the example commands in this guide, both the service name and the domain name are
mail.
example.com.
Both servers must meet the requirements described in the Zimbra Collaboration Suite Quick Start Guide, in addition to the requirements described here.
Go to the Red Hat Cluster Suite website, https://www.redhat.com/software/rha/cluster to view specific system requirements for cluster configurations using Red Hat Cluster Suite. If you are not familiar with the Red Hat Cluster Suite, read the documentation to understand how each of the components works to provide high availability.
The Zimbra Cluster software consists of install.pl, postinstall.pl, and
configure-cluster.pl scripts to automate the cluster configuration process and files that are used during the Zimbra cluster service operation.
Column one displays the steps preformed on the Active Host, column two, the steps preformed on the
Standby. The arrow identifies when you must continue the configuration on the other host.
IMPORTANT: These steps must be followed precisely because what you do on one node requires the other node to be in a specific state in order to be correctly configured.
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Each Zimbra cluster node requires Zimbra and Postfix users and groups The same user and group IDs must be used on both nodes.
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Type Done, when finished.
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3.
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Install the ZCS software. All packages should be installed. SNMP is optional. See the Quick Start Installation Guide for detailed installation instruction.
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When the DNS error to resolve MX displays, enter yes to change the domain name. Modify the domain name to the cluster service hostname (not the active node hostname).
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On the Main Menu make the following changes
When the ZCS installation is complete, there should be no reference to the active node hostname.
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./install.pl to begin the installation
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Each Zimbra cluster node requires Zimbra and Postfix users and groups The same user and group IDs must be used on both nodes.
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Type Done, when finished.
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When you install ZCS on the standby node, you must configure the node as described below.
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When the DNS error to resolve MX displays, enter yes to change the domain name. Modify the domain name to the cluster service name (not the server node name).
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LDAP master host name must be changed to point to the LDAP server running on the active node (mail.example.com). Note: this name is the service name, not the active node name.
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Change the LDAP password to the password set on the active node.
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zimbra-store - Admin user to create: Type No. An admin account should not be created on the standby node as it is already created on the active node.
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zimbra-logger
Disable logger on the standby. It is enabled on the active node.
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In order for remote management and postfix queue management, the ssh keys must be manually populated on each server.
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Run cluster postinstall.pl . Postinstall must be run on the standby node first because execution of postinstall requires that the LDAP server be running. Zimbra cluster post install script is used after Zimbra Collaboration Suite is installed on the servers to move the data files from the local disk to the volume(s) created on the SAN
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The Zimbra processes are stopped, various cluster-specific adjustments are made to the Zimbra Collaboration Suite installation, and unnecessary data files are deleted
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Mount the SAN volume (s). You can mount one volume for all services or you can mount ten separate volumes. The following command is to mount one volume for all services. To mount by label as root type: [root@node1 zcs] mount LABEL=mysanvol /opt/zimbra-cluster/mountpoints/mail.example.com.
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Run cluster postinstall.pl. To start the Zimbra post install cluster configuration script, cd to the zcs-cluster directory created in step 2. Type ./postinstall.pl to begin post install.
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The Zimbra processes are stopped, various cluster-specific adjustments are made to the Zimbra Collaboration Suite installation, and the data files are moved to the SAN volume(s).
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When the postinstall is complete use the Zimbra cluster configurator script to prepare Red Hat Cluster Suite to run the Zimbra Collaboration Suite. The cluster configurator script is run on only the active mailbox node.
The cluster configurator asks a series of questions to gather information about the cluster and generate the cluster configuration file, /etc/cluster/cluster.conf. This is the main configuration file of Red Hat Cluster Suite.
The cluster configurator installs the generated configuration file on each cluster node as /etc/cluster/cluster.conf.
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To start the Zimbra configuration script, cd to the zcs-cluster directory created in step 2. Type ./configure-cluster.pl. The configurator checks to verify that the server installation is correct.
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When Is installation finished on all cluster nodes? displays, type y to continue.
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Important: Each cluster on the same network must have a distinct name. Make sure you enter a name that is not in use! Each Red Hat Cluster Suite cluster on the same network must have a distinct name to avoid interfering with another Red Hat Cluster Suite cluster.
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For each service, you need to choose a preferred node to run on and enter the list of volumes to be mounted from the SAN.
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A Zimbra cluster service must mount service-specific data volumes. All service data can be placed on a single volume or the different types of data can be distributed over multiple volumes Choose the volume setup type, single volume or multiple volumes.
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Press Enter again to view a summary of the configuration.
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24.
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Bring down the cluster service IP address. At root@node1 ZCS-cluster]# type ip addr del xx.xx.xx.xx dev eth0.
You can now proceed with starting the RHCS daemons, which will bring up ZCS on one of the nodes.
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Important: In order to start the cluster daemons correctly, you must be logged on to each node before proceeding, and to see any errors, you should have two sessions open for each node. You enter a command for one node, then enter the same command for the second. You must enter each command on both nodes, before proceeding to the next command.
To start the Red Hat Cluster Service on a member, type the following commands in this order. Remember to enter the command on each node before proceeding to the next command.
The service rgmanager start command returns immediately, but initializing the cluster and bringing up the Zimbra Collaboration Suite application for the cluster services on the active node may take some time.
After all commands have been issued on both nodes, run clustat command on the active node, to verify that the cluster service has been started.
If the services does not relocate to the active node after several minutes, you can issue Red Hat Cluster Suite utility commands to manually correct the situation.
This disables the service by stopping all associated Zimbra processes, releasing the service IP address, and unmounting the service’s SAN volumes.
To enable a disabled service, run clusvcadm -e <service name> -m <node name>. This command can be run on any cluster node. It instructs the specified node to mount the SAN volumes of the service, bring up the service IP address, and start the Zimbra processes.
Go to the Zimbra administration console to check the status of the Zimbra cluster. The
Server Status page shows the cluster server, the node, the services running on the cluster server, and the time the cluster was last checked. The standby node is displayed as standby. If a service is not running, it is shown as disabled.
