HP XC System Software Administration Guide Version 3.0

DescriptionCommand
This command has a variety of subcommands that provide information about nodes.
Manpage: shownode(1)
shownode
The ssh_create_shared_keys command, used on a one-time basis, updates the appropriate
ssh key files in the user's $HOME/.ssh directory so they do not need to provide a login name
and password each time they log in to another node in the HP XC system or run jobs on those
nodes.
ssh_create_shared_keys
The startsys command causes specific actions to take place to start the entire HP XC system or
a subset of nodes.
Manpage: startsys(8)
startsys
The stopsys command causes specific actions to take place to halt the HP XC system or on a
subset of nodes.
Manpage: stopsys(8)
stopsys
The sys_check utility is a data collection tool that helps diagnose system errors and problems.
It creates an HTML report of your system's configuration (hardware and software).
Manpage: sys_check(8)
sys_check
Use this command to update the golden image on the image server based on the changes found
on the golden master. When client nodes request an updated golden image, they receive the latest
software in that image.
Manpage: updateimage(8)
updateimage
Interpreting 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].
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.
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:
Understanding the HP XC Command Environment 27