6 - Tru64 UNIX Cluster Hooks: File System Hierarchy, CDSL, & PID

Abstract

UNIX operating system enables a more seamless transition from a standalone system to a cluster. Once a system joins or forms a cluster, it becomes a member of the cluster. Tru64 UNIX version 5.0, the /etc/rc.config file has been split into two files. rc.config and rc. config, common. A CDSL is a symbolic link with the “{memb}” variable as part of the path. The “{memb}” is the “context”, or more appropriately, what is resolved to determine what the context. Configuring a network interface is a member-specific task. The rcmgr command is the recommended method for modifying the rc.config files on Tru64 UNIX. The file system hierarchy in Tru64 UNIX version 5 has been modified slightly from the version 4 layout. CDSL is a “behind-the-scenes” feature to make the life as an administrator easier. CDSL should be managed in a perfect way. Since a CDSL is a symbolic link, command can be used with the “s” option, although, it is highly recommended to use the mkcdsl command. The mkcdsl command is designed not to create just a CDSL, but to create a CDSL that can be maintained. Process Identities (PID) have been expanded to a 32-bit integer beginning in Tru64 UNIX version 5. In a stand-alone environment, there is no appreciable difference; for instance, PID 0 is still [kernel idle] and PID 1 is still the init daemon. The PID structure in a TruCluster environment, however, is defined to provide a unique range of process IDs (524288 PIDs/member).