OpenExtensions for z/VM

Hierarchical file systems

An OpenExtensions for z/VM user can create, store, and access the hierarchical file systems familiar to UNIX users (and similar to the file systems of DOS and OS/2).

With the hierarchical file system support provided by OpenExtensions for z/VM services:

  • Filenames and pathnames can be much longer than with traditional CMS file system names.
  • Terminals and communication pipes are accessed as files.
  • The hierarchical structure encourages an enterprise and its users to organize sets of files in a natural way (for example, by area, by department, by group of users, by user, and so forth).

OpenExtensions for z/VM provide facilities to make accessible (or remove from accessibility) different subsets of files in any hierarchical structure by logically mounting any particular hierarchy. A particular hierarchy that has been mounted can later be unmounted.

An OpenExtensions for z/VM hierarchical file system is a new type of CMS file system called a BFS (byte file system). BFS files and traditional CMS files can be copied back and forth.