Installation guide

<ip ref="127.143.131.100"/>
<apache ref="example_server"/>
</service>
<service autostart="0" domain="example_pri" exclusive="0"
name="example_apache2" recovery="relocate">
<fs name="web_fs2" device="/dev/sdd3" mountpoint="/var/www2"
fstype="ext3"/>
<ip address="127.143.131.101" monitor_link="yes"
sleeptime="10"/>
<apache config_file="conf/httpd.conf" name="example_server2"
server_root="/etc/httpd" shutdown_wait="0"/>
</service>
</rm>
</cluster>
7.6. Configuring Redundant Ring Prot ocol
As of Red Hat Enterprise Linux 6.4, the Red Hat High Availability Add-On supports the configuration
of redundant ring protocol.
When configuring a system to use redundant ring protocol, you must take the following
considerations into account:
Do not specify more than two rings.
Each ring must use the same protocol; do not mix IPv4 and IPv6.
If necessary, you can manually specify a multicast address for the second ring. If you specify a
multicast address for the second ring, either the alternate multicast address or the alternate port
must be different from the multicast address for the first ring. If you do not specify an alternate
multicast address, the system will automatically use a different multicast address for the second
ring.
If you specify an alternate port, the port numbers of the first ring and the second ring must differ by
at least two, since the system itself uses port and port-1 to perform operations.
Do not use two different interfaces on the same subnet.
In general, it is a good practice to configure redundant ring protocol on two different NICs and two
different switches, in case one NIC or one switch fails.
Do not use the i fd o wn command or the servi ce netwo rk sto p command to simulate network
failure. This destroys the whole cluster and requires that you restart all of the nodes in the cluster
to recover.
Do not use Netwo rkManag er, since it will execute the i fd o wn command if the cable is
unplugged.
When one node of a NIC fails, the entire ring is marked as failed.
No manual intervention is required to recover a failed ring. To recover, you only need to fix the
original reason for the failure, such as a failed NIC or switch.
To specify a second network interface to use for redundant ring protocol, you add an al tname
component to the clusterno d e section of the cl uster. co nf configuration file. When specifying
al tname, you must specify a name attribute to indicate a second host name or IP address for the
node.
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