Browse Prior Art Database

VM/ESA Virtual Disks In Storage

IP.com Disclosure Number: IPCOM000115287D
Original Publication Date: 1995-Apr-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Smith, NJ: AUTHOR

Abstract

Disclosed is a method for allocating system virtual storage as an emulated disk that may be shared among users of a multi-user operating system such as VM/ESA*. This emulated disk is known as a virtual disk in storage.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

VM/ESA Virtual Disks In Storage

      Disclosed is a method for allocating system virtual storage as
an emulated disk that may be shared among users of a multi-user
operating system such as VM/ESA*.  This emulated disk is known as a
virtual disk in storage.

      Data on a virtual disk in storage are temporary and volatile,
and are lost if the operating system is reinitialized.

      For ease of use, the emulated disk resembles a specific real
disk supported by the operating system.  In this way, users (which
may be operating systems in their own right), and applications may
exploit a virtual disk in storage with minimal or no changes to their
own code.  In addition, a VM virtual disk in storage may be shared in
ways similar to those used by operating system users for a real disk.

      The disk data reside in virtual storage, which is managed in
turn by the operating system's paging subsystem.  The actual disk
data may be in main storage or auxiliary storage, depending on how
recently they were referenced.

      Access control for shareable virtual disks in storage and the
data stored on them is provided in the same ways as those used for
real disks.  This can be done using passwords, access lists, or by
various other methods.

      The IBM* Enterprise Systems Architecture/370* provides for
address spaces.  The VM/ESA operating system exploits this facility,
providing address spaces for system use.  The method used for VM/ESA
virtual dis...