The /etc/mcrc file

The /etc/mcrc file, in conjunction with the cf.takeover.use_mcrc_file option, should be used on MetroCluster configurations in which the partner nodes reside on separate subnetworks.

Normally, when a node (for example, nodeA) takes over its partner (nodeB), nodeA runs nodeB's /etc/rc file to configure interfaces on nodeA to handle incoming traffic for the taken-over partner, nodeB. This requires that the local and partner addresses are on the same subnetwork.

When the cf.takeover.use_mcrc_file option is enabled on nodeA, nodeA will use nodeB's /etc/mcrc file upon takeover, instead of nodeB's /etc/rc file. The ifconfig commands in the /etc/mcrc file can configure IP addresses on nodeA's subnetwork. With the correct ifconfig, virtual IP (VIP), and routing commands in the /etc/mcrc file, the resulting configuration allows hosts connecting to nodeB to connect to node A.

Note: The /etc/mcrc file must be maintained manually and kept in sync with the /etc/rc file.

Examples of /etc/rc and /etc/mcrc files

NodeA's /etc/rc file, which configures its local addresses and a partner address (which matches the address configured in NodeB's /etc/mcrc file):

hostname nodeA
ifconfig e0a 10.1.1.1 netmask 255.255.255.0
ifconfig e0a partner 10.1.1.100
ifconfig vip add 5.5.5.5
route add default 10.1.1.50 1
routed on
options dns.domainname mycompany.com
options dns.enable on
options nis.enable off
savecore
NodeA's /etc/mcrc file, which configures a partner address on NodeB's subnetwork:
hostname nodeA
ifconfig e0a 20.1.1.200 netmask 255.255.255.0
ifconfig vip add 5.5.5.5
route add default 20.1.1.50 1
routed on
options dns.domainname mycompany.com
options dns.enable on
options nis.enable off
savecore
NodeB's /etc/rc file, which configures its local addresses and a partner address (which matches the address configured in NodeA's /etc/mcrc file):
hostname nodeB
ifconfig e0a 20.1.1.1 netmask 255.255.255.0
ifconfig e0a partner 20.1.1.200
ifconfig vip add 7.7.7.7
route add default 20.1.1.50 1
routed on
options dns.domainname mycompany.com
options dns.enable on
options nis.enable off
savecore
NodeB's /etc/mcrc file, which configures a partner address on NodeA's subnetwork:
hostname nodeB
ifconfig e0a 10.1.1.100 netmask 255.255.255.0
ifconfig vip add 7.7.7.7
route add default 10.1.1.50 1
routed on
options dns.domainname mycompany.com
options dns.enable on
options nis.enable off
savecore