System Configuration and Imaging Overview

System Configuration Process

The system configuration process, developed by HP, is the method by which the topology of the system is automatically discovered, applied, and stored in the configuration database after the installation of the head node has been completed.

The system topology is defined based on the manner in which the head and client nodes are connected to the administration network when the nodes are cabled into the appropriate switches.

The system configuration procedure described in this chapter consists of running the following HP XC commands and utilities:

System Imaging Process

The SystemImager, an open source software component of the HP XC system, provides a simplified method for automating the installation of large Linux clusters. SystemImager provides the foundation for the image replication and distribution environment used to install client nodes in HP XC system.

As part of the initial software installation, the head node is configured as the golden client, which is the node that represents the configuration from which all other nodes are replicated. Next, a golden image is created from the golden client, which is a replication of the local file system directories and files, starting from root (/). The golden image is stored on the image server, which is also resident on the head node in this release.

When nodes are instructed to PXE or network boot from their network adapter attached to the administration network, the nodes automatically proceed through an installation process that replicates the golden client and does the following:

When the automatic installation process completes, each node is rebooted and continues its configuration process, eventually ending with the login prompt.

System Configuration and Imaging Log Files

A record of the configuration process is stored in the /var/log/nconfig.log file.

Logging of the system imaging process is stored in the following files:

The /hptc_cluster/adm/logs/imaging.log file contains log information produced during the imaging and node configuration processes. You can use the information in this file to diagnose imaging issues, such as nodes not booting correctly or failing during the imaging operation. The nconfigure portion of the log file provides useful information during the first boot after a node has been imaged. If a node configuration fails, the node is put into single-user mode with network access. The node is not allowed to join the cluster without user intervention. The node or nodes that are put into single-user mode are listed in the imaging.log file.

Two system services based on syslog-ng log the UDP based information sent by each client during installation and the node configuration phase (nconfig). The hptc-ire-serverlog service runs persistently on the imaging server. It is responsible for accepting UDP messages from the imaging client and from the hptc-ire-clientlog service running when a node is running through its nconfig phase. The hptc-ire-clientlog service is managed by autoinstall and the nconfig process. It is only started during these processes and turned off after the processes have been completed.

The rsync log daemon is responsible for logging start and completion time stamps for imaging and golden image updates in the /var/log/systemimager/rsyncd file. The information is sent through TCP for reliability. This is a required service because imaging completion timestamps are used to generate the per node entries in the /tftpboot/pxelinux.cfg file that denote a system has imaged successfully.