HP Insight Cluster Management Utility - Manual (Page 81)

The onesis_pxeboot directory contains
•
The vmlinuz kernel.
•
The initrd.img initial ramdisk.
•
The pxelinux.0 PXE-boot loader.
•
The pxelinux.cfg/ directory where the PXE-boot files for each node will be installed.
These components are used during the PXE-boot process to boot the compute nodes into a diskless
environment.
The onesis_pxeboot_template file is the PXE-boot template file. It contains keywords that are
replaced by node-specific information to create the PXE-boot file for that compute node. This occurs
when a node is added to this HP Insight CMU diskless logical group. To make changes to the
kernel arguments, for example to change the PXE-boot network from eth0 to eth1, edit this file.
However, this template file functions properly as is.
The reconf-onesis-image.sh file is run after the image creation process completes. System
administrators can automate any desired customizations to the image with this file; for example,
to add mountpoints to the etc/fstab file in the golden image so that all of the diskless compute
nodes will mount a shared file system on bootup. That customization can be performed manually,
or it can be done with this script. Another common customization example is configuring a second
network on the diskless compute nodes, such as an InfiniBand network. This example is documented
in the comments of this file and in the reconf-onesis-snapshot.sh file.
The reconf-onesis-snapshot.sh file is run after a node is added to this HP Insight CMU
oneSIS diskless logical group. System administrators can script any node-specific customizations
to the golden image with this file.
Be aware that some node-specific customizations require scripting in both the
reconf-onesis-image.sh
script and in the reconf-onesis-snapshot.sh file. An example
of this is configuring TCP IP addresses over InfiniBand, which is documented in both files. The
reconf-onesis-image.sh
script handles configuring the ifcfg-ib0 as a writable file in
oneSIS and creating the template file, while the reconf-onesis-snapshot.sh script handles
the per-node IP address configuration for each node.
5.8.3.6 Manage the writeable memory usage by the oneSIS diskless clients
OneSIS allows you to configure the amount of memory allocated for use by the oneSIS writable
file system that is created on bootup. The RAMSIZE setting in the onesis/etc/sysimage.conf
file controls the amount of memory allocated for oneSIS. By default, HP Insight CMU configures
this setting to 500m which is 500 MB of memory. Change this setting as appropriate.
5.8.3.7 Adding nodes and booting the diskless compute nodes
After the oneSIS diskless golden image is ready and the per-node configurations are set:
1.
Add nodes to this HP Insight CMU diskless logical group.
2. Boot the nodes over the network.
3. Select this logical group name.
When the nodes boot up, the kernel and the initrd:
•
Mount the read-only root file system.
•
Configure the oneSIS/ram tmpfs file system.
•
Copy the appropriate read-writable files into that file system.
•
Proceed with the configured bootup sequence.
5.8 HP Insight CMU diskless environments 81