Browse Prior Art Database

Updating Operating Systems and Applications on a Running System

IP.com Disclosure Number: IPCOM000114331D
Original Publication Date: 1994-Dec-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 4 page(s) / 102K

Publishing Venue

IBM

Related People

Grantz, JA: AUTHOR [+3]

Abstract

Disclosed is a methodology to update applications and microkernel based operating systems while the system is in use. Because, many of the files to be updated are locked, systems like OS/2* 2.1 require a maintenance system, a small operating system whose sole purpose is to apply updates. The maintenance system would be installed along side the original system, and the service installer would be run on the maintenance system. This disclosure illustrates a solution to this problem.

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Updating Operating Systems and Applications on a Running System

      Disclosed is a methodology to update applications and
microkernel based operating systems while the system is in use.
Because, many of the files to be updated are locked, systems like
OS/2* 2.1 require a maintenance system, a small operating system
whose sole purpose is to apply updates.  The maintenance system would
be installed along side the original system, and the service
installer would be run on the maintenance system.  This disclosure
illustrates a solution to this problem.

      The installation of service needs to be done as a single atomic
transaction.  Either all of the updates to the application or
operating system component must be completed, or none of the updates
should be attempted.  If service is not applied atomically the
resulting application or system can be left in an inconsistant and
possibly inoperable state.  The presence of Locked files prevents
this from taking place.

      Serialization of file reads and writes, as well as changes in
the file handle seek position are supported by the file system.  If a
program has opened a file with either a read lock or a write lock,
another program will not be granted a write token on the opened file.
On an OS/2 system the loader opens files containing executable code
and keeps the files open until the using process(es) terminate(s).
An installer must only apply service to applications and operating
system components where all of the files to be updated are unlocked,
and will only be locked by the installer during the update operation.

      There are two execution environments available to programs
running on a microkernel based operating system.  The first is
created by the microkernel, and will be refered to as the Personality
Neutral environment.  The second is created by the set of servers
running on the microkernel.  The set of servers create a unique
application environment or personality.  Fig. 1 shows an OS/2
application environment.

      To avoid locked files the installation of service needs to be
done in a minimal system environment when OS/2 applications, and the
OS/2 personality are not running.  The Personality Neutral
environment is one place where this can be done.  However, running an
installer in a personality neutral environment is not a complete
solution.

      In order to apply service to the Microkernel, Device...