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Appendix A. Upgrading From Red Hat Enterprise Linux 6 High Availability Add-On
This appendix provides an overview of upgrading Red Hat Enterprise Linux High Availability Add-On from release 6 to release 7.
A.1. Overview of Differences Between Releases
The Red Hat Enterprise Linux 7 High Availability Add-On introduces a new suite of technologies that underlie high-availability systems. These technologies are based on Pacemaker and Corosync and they replace the CMAN and RGManager technologies from previous releases of the High Availability Add-On. Below are some of the differences between the two releases. For a more comprehensive look at the differences between releases, see the appendix titled "Cluster Creation with rgmanager and with Pacemaker" from the Red Hat Enterprise Linux High Availability Add-On Reference.
- Configuration Files — Previously, cluster configuration was found in the
/etc/cluster/cluster.conffile, while cluster configuration in release 7 is in
/etc/corosync/corosync.conffor membership and quorum configuration and
/var/lib/pacemaker/cib/cib.xmlfor cluster node and resource configuration.
- Executable Files — Previously, cluster commands were in
ccsby means of a command line,
lucifor graphical configuration. In Red Hat Enterprise Linux 7 High Availability Add-On, configuration is done by means of
pcsat the command line and the
pcsdWeb UI configuration at the desktop.
- Starting the Service — Previously, all services including those in High Availability Add-On were performed using the
servicecommand to start services and the
chkconfigcommand to configure services to start upon system boot. This had to be configured separately for all cluster services (
ricci. For example:
service rgmanager start chkconfig rgmanager onFor Red Hat Enterprise Linux 7 High Availability Add-On, the
systemctlcontrols both manual startup and automated boot-time startup, and all cluster services are grouped in the
pcsd.service. For example:
systemctl start pcsd.service systemctl enable pcsd.service pcs cluster start -all
- User Access — Previously, the root user or a user with proper permissions can access the
luciconfiguration interface. All access requires the
riccipassword for the node.In Red Hat Enterprise Linux 7 High Availability Add-On, the
pcsdWeb UI requires that you authenticate as user
hacluster, which is the common system user. The
rootuser can set the password for
- Creating Clusters, Nodes and Resources — Previously, creation of nodes were performed with the
ccsby means of a command line or with
lucigraphical interface. Creation of a cluster and adding nodes is a separate process. For example, to create a cluster and add a node by means of the command line, perform the following:
ccs -h node1.example.com --createcluster examplecluster ccs -h node1.example.com --addnode node2.example.comIn Red Hat Enterprise Linux 7 High Availability Add-On, adding of clusters, nodes, and resources are done by means of
pcsat the command line, or the
pcsdWeb UI. For example, to create a cluster by means of the command line, perform the following:
pcs cluster setup examplecluster node1 node2 ...
- Cluster removal — Previously, administrators removed a cluster by deleting nodes manually from the
luciinterface or deleting the
cluster.conffile from each nodeIn Red Hat Enterprise Linux 7 High Availability Add-On, administrators can remove a cluster by issuing the
pcs cluster destroycommand.