HP XC System Software Installation Guide Version 3.2

Any node with this role may be called upon to execute jobs scheduled by the users. Nodes with
this role are also often called compute nodes.
It is your responsibility to remove this role on a node if it is not wanted or required.
To enable monitoring of the nodes, run the Nagios remote plug-in execution agent on nodes
with the compute role.
F.3.5 Console_network Role
The console_network role enables you to map HP XC services with physical console
requirements to the appropriate nodes. By default, this role is assigned to the same set of nodes
as the management_hub role. In system installations in which only specially designated nodes
can access the console network, you can assign this role to those nodes instead, and the
management and monitoring tools use only those nodes.
You must assign the console_network role to nodes that have console access. Otherwise,
Nagios plug-ins that require console access will not collect data.
The configuration and management database names of the services provided by this role are as
follows:
• Console management facility master (cmf)
• Console access (cpaccess)
F.3.6 Disk_io Role
Nodes with the disk_io role provide access to storage and file systems mounted locally on the
node. This role can be located on any node that provides local file system access to all nodes
using NFS. Assign this role to any node that is exporting SAN storage.
The configuration and management database for the NFS Server service supplied by this role is
nfs_server.
Nodes with this role normally reside in the utility cabinet of the cluster and have the most direct
access to storage.
You can assign other roles to a node with this role. However, you must be careful not to overload
the node so it can provide adequate NFS service.
F.3.7 External Role
The external role supplies the NAT server service, which does network address translation
within the cluster. This enables applications to access nodes that do not have an external network
connection. The configuration and management database name of the service supplied by this
role is nat.
Assign this role only to nodes on which you are configuring an external network connection.
If you installed remote graphics software, you must configure an external Ethernet device (the
external NICs) on the SVA nodes.
The system can have multiple nodes defined with the external role, supplying multiple NAT
servers to ease network traffic congestion.
To achieve improved availability of NAT, assign the external role to both nodes in the
availability set. If you assign the external role to another node in the system, it will be ignored.
Applications have no need to be aware of the actual internal IP address of a compute node
because a NAT server node handles all network requests.
F.3.8 Login Role
Nodes with the login role accept login sessions of users. A user can submit jobs from the
command line on a node with a login role. The jobs are distributed among compute nodes to
process the job. Nodes assigned with a login role must have a configured external network
connection.
212 Description of Node Roles, Services, and the Default Configuration