VME and FSI differences

Virtual Machine Environment (VME) is a set of resources obtained from the host operating system at utilization time and is the compatibility layer for applications.

File System interface (FSI) is the primary file in the host environment and has multiple sources.

Some of the differences between the VME and FSI are:

VME
  • Set of resources obtained from Windows or UNIX at initialization that display the functions and characteristics of a D3 computer system, and are shared by several D3 processes. For example, a real machine (the Windows or UNIX-based operating system) emulates a virtual machine (the D3 computer system), which then has disk space, tape drives, printers, terminals, users, and the D3 file system and language.

  • D3 UNIX Several virtual machines can coexist on any given single hardware platform.

  • Subsystem of D3 Windows that provides an ASCII mode that is backwards compatible with previous Rocket applications.

  • D3 Windows VME is required in order to start and run the FSI. It acts as a front-end to the FSI.

  • idn correlative in VME can start from 0 (for example, id0).

  • The list-lockq command is supported for VME locks.

  • Allows retrieving the Date and Time a program was last run and a count of the number of times a program has been run since the last re-compile. This information can be retrieved from the object-pointer item in the dictionary of the program.

FSI
  • Server is a multi-threaded process that can service several clients requests.

  • The files are distinct objects on the network, locks and disk space are handled independently of other files.

  • Server also centralizes the record locks associated with the tables it manages.

  • idn correlative must start from 1 (for example, id1). id0 in the FSI is ignored.

  • The list-lockq command is not supported for FSI locks.

  • Disallows retrieving the Date and Time a program was last run.

Note:
  • VME: file-of-files (hyphenated)

  • FSI: FileOfFiles (not hyphenated)

In general terms, when referring to either file, file of files file is used.