Defining the root file system

Use the ROOT statement in the BPXPRMxx member of SYS1.PARMLIB to define which file system is the root file system. You have two choices: HFS and zFS. The zFS file system is the preferred file system, and continued use of HFS is not encouraged.

Figure 1 shows the sample BPXPRMxx member. The ROOT statement is as follows:
ROOT   FILESYSTEM('OMVS.ROOT')
       TYPE(ZFS)
       MODE(RDWR)

The root file system is the starting point for the overall hierarchical file system. It contains the root directory and any related files or subdirectories.