HP XC System Software Administration Guide Version 3.0

Figure 1-1. LVS View of Cluster LVS View of Cluster
User
LVS
Single System View of Cluster
HP XC Cluster
Network Time Protocol
One node in an HP XC system acts as the internal Network Time Protocol (NTP) server for all the other nodes.
By default this is the head node. All other nodes are NTP clients of this server.
You can specify where the internal NTP server gets the time. You can specify up to three external time sources
if the internal server has a connection to an outside network. You can also choose to use the internal server's
own clock as the time source.
Should something go wrong and you notice a problem with the clocks synchronizing on any nodes, verify
the internal server's /etc/ntp.conf file and the ntp.conf file on the nodes that are experiencing the
problem.
Other tools, such as ntpq and ntpdc, are also available. For more information, see ntpd(1), ntpq(1),
and ntpdc(1) and the ntp.conf file.
Network Address Translation
The HP XC system uses Network Address Translation (NAT) to enable nodes in the HP XC system without
direct external network connections to open outbound network connections to external addresses. NAT
enables application nodes to access network-available resources without the additional network management,
resources, or load of making application nodes part of an external public network.
Network Information Service
The configuration of Network Information Service (NIS) on an HP XC system is an optional step that is useful
for easing user management and helpful for SLURM and LSF-HPC use. You may decide to set up your user
management with some other software, such as Lightweight Directory Access Protocol (LDAP).
Use either of the following methods for setting up NIS on your HP XC system:
30 HP XC Administration Environment