DSM - Disk Space Manager

The necessary tool to avoid a build up of unnecessary data

Save substantial amounts of disk space. DSM lets you do a full analysis of all objects in your system and reclaim wasted space.

Any typical AS/400 installation contains tens of thousands of objects. These objects can be classified as



IBM system objects



Active user objects


Inactive user objects

Because of the large number of objects it is very difficult to manage them manually. Inactive objects clutter the disk and active objects may use more space than they need.

DSM helps you to identify these problems by printing exception reports that let you concentrate only on the objects that need attention. It has tools to let you reclaim the wasted disk space.

IBM system objects

IBM system objects, in principle should not be touched. When shipped they are already at their minimum size. However some system libraries such as QGPL, QRECOVERY and QRPLOBJ require periodic inspection and cleanup.

Active user objects

These objects can be reduced in size using one of three techniques



Source physical tiles can be compressed


Programs can have observability removed


Data physical files can be reorganized

Compressing source files shrinks its size typically by more than 50%. DSM uses a very fast machine interface (assembler) operation to perform compression and decompression. Removing program observability reduces its size by up to 70%. Reorganizing data physical files brings variable savings depending on the installation.

Inactive user objects

These objects should be deleted (with or without prior backup). DSM helps you to positively identify inactive objects.

DSM looks at some big disk eaters. Save files and journal receivers are two of them. Spooled files are another. When you delete a spooled file, the operating system leaves an empty physical member in library QSPL waiting to be reused. Some installations have hundreds or even thousands of these inactive members doing nothing except occupying valuable disk space.

When DSM deletes a spooled file it removes the whole thing including these empty members.

DSM also analyzes the history log and problem log.

Duplicate objects analysis

Large space savings can be achieved by removing duplicate objects. Many times objects or even whole libraries are duplicated just for a quick test. But when the test ends the duplicate objects stay in the disk, unnoticed.

DSM has special options to find out duplicate objects. If both objects have the same name, DSM will catch them. If they have different names but the same root name (example ITEM and ITEMOLD) DSM prints reports where they are shown close enough, to let an expert eye spot them.

DSM functions

Disk space analysis

This function lets you print eighteen reports with several levels of summary/detail.


Library name summary


Object type summary


Object attribute summary


Object name detail

In each report you may select the range of libraries and object types/attributes to include or to exclude. A convenient selection lets you also exclude objects and/or libraries below a minimum size.

Reports can be printed either in the conventional alphabetic sequence or in descending object size sequence.

For example a very popular option is a short report that lists libraries in descending library size sequence.

Reclaim space analysis

This function prints nine reports that let you perform a "what if' analysis on your objects. Example - How much space do I save if I delete all superseded save files? Or, if I delete all spooled files that are more than 30 days old?

Reclaim disk space

This option includes ten commands you can use to clean up your disk.

In principle these commands only perform either harmless or recoverable operations. Example - A command lets you remove observability of programs. But later on you can recompile the programs to make them observable again. Another command lets you delete duplicate objects. But DSM first checks that an original object exists.

Auxilliary functions

This option lets you operate on compressed source files (edit members,. compile members etc.), print/display the system documentation and do general maintenance of the DSM system.

For more information or a free fully functional demo with manual:

download DSM (7.3 Mb)

or contact us via the traditional communication channels:

InterData Systems, Inc.
522 Balliol St.
Toronto, ON Canada,   M4S 1E3
Phone: 1 (416) 932-8372
Fax: 1 (416) 352-5457