Managing HP Serviceguard for Linux, Tenth Edition, September 2012

start the cluster depending on whether all nodes are currently down (that is, no cluster
daemons are running), or whether you are starting the cluster daemon on an individual
node.
Note the distinction that is made in this chapter between adding an already configured
node to the cluster and adding a new node to the cluster configuration. An already
configured node is one that is already entered in the cluster configuration file; a new
node is added to the cluster by modifying the cluster configuration file.
NOTE: Manually starting or halting the cluster or individual nodes does not require
access to the quorum server, if one is configured. The quorum server is only used when
tie-breaking is needed following a cluster partition.
Starting the Cluster When all Nodes are Down
You can use Serviceguard Manager, or the cmruncl command as described in this
section, to start the cluster when all cluster nodes are down. Particular command options
can be used to start the cluster under specific circumstances.
The -v option produces the most informative output. The following starts all nodes
configured in the cluster without a connectivity check:
cmruncl -v
The -w option causes cmruncl to perform a full check of LAN connectivity among all
the nodes of the cluster. Omitting this option will allow the cluster to start more quickly
but will not test connectivity. The following starts all nodes configured in the cluster with
a connectivity check:
cmruncl -v -w
The -n option specifies a particular group of nodes. Without this option, all nodes will
be started. The following example starts up the locally configured cluster only onftsys9
and ftsys10. (This form of the command should only be used when you are sure that
the cluster is not already running on any node.)
cmruncl -v -n ftsys9 -n ftsys10
CAUTION: HP Serviceguard cannot guarantee data integrity if you try to start a cluster
with the cmruncl -n command while a subset of the cluster's nodes are already running
a cluster. If the network connection is down between nodes, using cmruncl -n might
result in a second cluster forming, and this second cluster might start up the same
applications that are already running on the other cluster. The result could be two
applications overwriting each other's data on the disks.
Adding Previously Configured Nodes to a Running Cluster
You can use Serviceguard Manager, or HP Serviceguard commands as shown, to bring
a configured node up within a running cluster.
244 Cluster and Package Maintenance