Utilization of the RAM disk

Most deviations in node behavior result from differences in configuration files in the root filesystem. For example, some nodes may need to mount different filesystems than those listed in the default configuration. Those nodes would require a different configuration in the /etc/fstab file.

For any file requiring variations between nodes, oneSIS replaces the file with a symbolic link pointing to its corresponding path in /ram. The original file is moved to a file with the same name, but with a `.default' extension.

At boot time, each node determines its role and uses the version of the file that corresponds to that node's class (see figure 1). Any node not configured to use an alternate file or directory uses the original `.default' file. This technique can be used to achieve different behavior for any node or class of nodes.

Figure: disk Usage. Configuration files for each class of node are linked back to at run-time.