HP XC System Software Administration Guide Version 3.1

The node assigned this service is the MySQL configuration database server for this system. For
additional information on the configuration database, see “Configuration and Management Database”
(page 34) .
• Dynamic Host Control Protocol (DHCP) server
This service assigns IP addresses for all devices on the internal network based on the DHCP server
node's Machine Access Control (MAC) address.
• Power daemon service
The power subsystem daemon enables you to turn on, turn off, cycle, and reset power on individual
nodes, and also report whether a node's power is on or off.
This daemon is automatically assigned to the head node.
For additional information on nodes and services, see the HP XC System Software Installation Guide.
1.1.3 Roles
A role is defined as an aggregate of related services.
1.2 File System
Proper maintenance of the file system is crucial to the operation of the HP XC system. This section describes
key directories and offers guidelines for the maintenance of the file system.
The basic file system layout is the same as that of a standard Linux file system. Additions to the layout for
the HP XC system are described in this section.
Figure 1-1 illustrates the top of the file system hierarchy for a node in the HP XC system.
Figure 1-1 HP XC File System Hierarchy
IMPORTANT: The HP XC system relies on key files. Interfering with these files can cause the system to
fail. The best way to avoid this situation is to respect the placement of directories and files, especially when
installing software packages. The file system layout is structured to isolate the files specific to the HP XC
System Software from base operating system files. This isolation enables flexibility and ease of potential
upgrades of the system software and keeps software from conflicting with user-installed software. You
can avoid many pitfalls by strictly maintaining separation between the HP XC System Software and other
software.
The following sections describe the base operating system files, directories specific to the HP XC System
Software, system software configuration files, and log files.
1.2.1 Key Operating System Directories
Following are the key directories:
/bin
Holds the binary executable files that any user can invoke.
/sbin
Holds the binary executable files that are specifically for the system administrator
or designated privileged users.
1.2 File System 27