Summary of various file systems in a shared environment

This topic introduces the various file systems and terms needed to use the shared file system support. Table 1 summarizes the file systems that are needed in a sysplex environment. As you study the illustrations of file system configurations, you can refer back to this table.

Table 1. Various file systems that exist in a sysplex. This table lists a summary of the various file systems in a shared environment
Name	Characteristics	Purpose	How created
Sysplex root	It contains directories and symbolic links that allow redirection of directories. Only one sysplex root file system is allowed for all systems participating in a shared file system.	The sysplex root is used by the system to redirect addressing to other directories. It is very small and is mounted read-only.	For the zFS file system, the user runs the BPXISYZR job. For the HFS file system, the user runs the BPXISYSR job.
System specific	It contains data specific to each system, including the /dev, /tmp, /var, and /etc directories for one system. There is one system-specific file system each system participating in a shared file system. When using the TSO/E MOUNT command to set up system-specific file systems, specify the UNMOUNT parameter. Then, if data sets are replaced during a reIPL, the new data sets will be mounted as the original file systems. Use the NORWSHARE mount parameter to mount zFS system-specific file systems.	The system-specific file system is used by the system to mount system-specific data. It contains the necessary mount points for system-specific data and the symbolic links to access sysplex-wide data, and must be mounted read/write.	For the zFS file system, the user runs the BPXISYZS job on each participating system. For the HFS file system, the user runs the BPXISYSS job on each participating system.
Version In a sysplex, the version file system is the new name for the root file system.	It contains system code and binaries, including the /bin, /usr, /lib, /opt, and /samples directories. IBM® delivers only one version root; you might define more as you add new system levels and new maintenance levels.	The version file system has the same purpose as the root file system in the non-sysplex world. It must be mounted read-only. See Mounting the version file system for a complete description of the version file system.	IBM supplies this file system in the ServerPac. CBPDO users create the file system by following steps defined in the Program Directory.