What do I need to do when replacing a motherboard?

After replacing a failed motherboard, steps need to be taken to allow the network configuration in Linux work without disruption.  Here, we outline the steps to take on an Enterprise Linux system.  Console access is required for the node getting the replacement; the local steps can be taken as soon as the motherboard is replaced and the node is powered back up for convenience.

• Update the act_nodes.conf file
• Regenerate the DHCP configuration
• Update the udevd rules
• Reboot
• Update IPMI configuration

Since we replaced the motherboard, the MAC addresses of the onboard NICs have changed. These need to be entered into the act_node file on the head node (/act/etc/act_nodes.conf) by changing out the line for the respective node.

node06 eth0=52:54:00:95:14:3f,eth1=52:54:00:d7:90:af

Then run:

act_cfgfile --dhcp --prefix=/

Next, you need to manually login to the node itself, either locally or over Serial-over-LAN console if configured. Login to the node, then edit: /etc/udev/rules.d/70-persistent-net.rules

• Remove the existing lines for eth0 and eth1 (plus eth2 and eth3 on quad Ethernet motherboards.)

After editing, reboot the node. Once the node boots back up, it should be remotely accessible again now that it has the current mac addresses mapped properly.

The last steps to perform are for reconfiguring IPMI on the node since the IPMI BMC on the original motherboard was replaced as well.

$ act_exec -n node06 "service ipmi start"
$ act_ipmi_netcfg -n node06

For the following command, take the output and use it to update /etc/dhcpd.d/ipmi.conf by looking for the node06 line and putting in the new MAC address.

$ act_ipmi_netcfg -n node06 --dump_dhcp
$ service dhcpd restart
$ act_exec -n node06 "service ipmi stop"
$ act_ipmi_log -n node06 setdate

The node should be fully operational after this.