HP XC System Software Administration Guide Version 4.0

Table 1-2 HP XC System Commands (continued)
DescriptionCommand
The xcxclus and xcxperf X11 clients that enable you to monitor the performance
of multiple and individual systems.
The xcxclus graphic utility that enables you to monitor a number of nodes
simultaneously.
The xcxperf utility provides a graphic display of node performance for a variety of
metrics.
These utilities are described in the HPCPI and Xtools User Guide.
Manpages: xcxclus(1) and xcxperf(1)
xcxclus
xcxperf
1.3.2 The nodelist Parameter
The nodelist parameter, used in several HP XC system commands, indicates one or more
nodes. You can use brackets, hyphens, and commas in the nodelist parameter:
[ ]
Brackets indicate a set of nodes. You can use only one set of brackets for each instance of
the nodelist parameter.
-
A hyphen indicates a range of nodes.
,
A comma separates node definitions.
For example, the nodes n1 n2 n3 n5 can be expressed in the nodelist parameter as n[1-3,5].
An example in “Using the pdsh Shell” illustrates the use of a nodelist parameter to specify a
group of nodes.
1.3.3 Executing a Command on Multiple Nodes
You can enter the HP XC system commands at the command line or invoke them remotely on a
node in the HP XC system using the pdsh shell or the cexec command. These commands enable
you to execute a command on multiple nodes at the same time. Use the cexec command when
you need to log the command. Use the pdsh command when logging is not required.
Some commands, like the power command, accept a list of nodes as a parameter; this parameter
is often referred to as a nodelist. These commands affect the nodes directly, without the need
for the pdsh or cexec commands.
You can use the HP XC commands in a cron script like any other command.
1.3.3.1 Using the pdsh Shell
The open source Parallel Distributed Shell (pdsh) command is a multithreaded remote shell
client that executes commands on multiple nodes in parallel. You can specify all nodes, a given
number of nodes, or only certain nodes to perform the command or commands passed as
arguments to the pdsh command.
By default, the pdsh shell can issue 32 simultaneous remote commands at a time. You can override
this default with the -f option.
The pdsh shell relies on the ssh transport mechanism. Ensure that ssh is properly installed on
the system; changes to the ssh configuration might cause the pdsh shell to fail. Although the
pdsh shell is capable of using several remote shell services, including rsh and ssh, the security
settings of the HP XC system make ssh the shell of choice.
The format of this command is:
pdsh -[options] " command ... "
1.3 HP XC Command Environment 33