Ensuring Consistency of Kernel Configuration

NOTE: If a NIC fails, the affected node will be able to fail over to a standby LAN so long as the node is running in the cluster. But if a NIC that is used by Serviceguard fails when the affected node is not running in the cluster, Serviceguard will not be able to restart the node. (For instructions on replacing a failed NIC, see “Replacing LAN or Fibre Channel Cards” (page 327).)

NOTE: If you plan to use cmpreparecl (1m) (orcmpdeploycl (1m), which calls cmpreparecl), the /etc/hosts and /etc/nsswitch.confconfiguration described the procedure that follows will be done automatically, but you should still read the entire subsection and make sure you understand the issues.

1.Edit the /etc/hosts file on all nodes in the cluster. Add name resolution for all heartbeat IP addresses, and other IP addresses from all the cluster nodes; see “Configuring Name Resolution” (page 168) for discussion and examples.

NOTE: For each cluster node, the public-network IP address must be the first address listed. This enables other applications to talk to other nodes on public networks.

2.If you are using DNS, make sure your name servers are configured in /etc/resolv.conf, for example:

domain cup.hp.com search cup.hp.com hp.com nameserver 15.243.128.51 nameserver 15.243.160.51

3.Edit or create the /etc/nsswitch.conf file on all nodes and add the following text, if it does not already exist:

•for DNS, enter (two lines):

hosts: files [NOTFOUND=continue UNAVAIL=continue] dns [NOTFOUND=return UNAVAIL=return]

ipnodes: files [NOTFOUND=continue UNAVAIL=continue] dns [NOTFOUND=return UNAVAIL=return]

•for NIS, enter (two lines):

hosts: files [NOTFOUND=continue UNAVAIL=continue] nis [NOTFOUND=return UNAVAIL=return]

ipnodes: files [NOTFOUND=continue UNAVAIL=continue] nis [NOTFOUND=return UNAVAIL=return]

If a line beginning with the string hosts: or ipnodes: already exists, then make sure that the text immediately to the right of this string is (on one line):

files [NOTFOUND=continue UNAVAIL=continue] dns [NOTFOUND=return UNAVAIL=return]

files [NOTFOUND=continue UNAVAIL=continue] nis [NOTFOUND=return UNAVAIL=return]

This step is critical, allowing the cluster nodes to resolve hostnames to IP addresses while DNS, NIS, or the primary LAN is down.

4.Create a $SGCONF/cmclnodelist file on all nodes that you intend to configure into the cluster, and allow access by all cluster nodes. See “Allowing Root Access to an Unconfigured Node” (page 166).

NOTE: HP recommends that you also make the name service itself highly available, either by using multiple name servers or by configuring the name service into a Serviceguard package.