Managing Serviceguard Nineteenth Edition, Reprinted June 2011

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 314).)
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 159) 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]
or
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 157).
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.
Ensuring Consistency of Kernel Configuration
Make sure that the HP-UX kernel configurations of all cluster nodes are consistent with the expected
behavior of the cluster during failover. In particular, if you change any kernel parameters on one
Preparing Your Systems 161