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Beam: A Tool for Flexible Software Update

Thomas Eirich
University of Erlangen-Nrnberg, Germany

Abstract

Today's workstations often have a limited local disk space. Besides putting the home of the workstation's owner onto the local disk it is reasonable to place frequently used software packages on the disk, too. This reduces network traffic and makes a workstation more independent from file servers. Of course, the replicated software must be kept consistent with the versions on the file servers. This should be done by an automatic update mechanism.

Copying software packages in their entirety would quickly fill up the local disk space. Especially this problem is addressed by Beam. Copying the whole software package is merely the simplest form of Beam's update possibilities. A system administrator can rely on powerful features for writing update scripts: merging of several source trees, enhanced file name generation, embedded Perl code, a rich set of update commands which can be arbitrarily combined to form complicated update rules. Additionally, Beam has a PACK concept which allows easy adaptation of the update process to the usage pattern of a workstation's owner. To save space on the local disk the user can omit those parts of software packages which are not needed at all (e.g., foreign language user interface) or which are of less interest (e.g., manuals for experienced users). These parts are not missing on the workstation because a symbolic link to the server version is inserted.

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