To prohibit access to a DAM file cataloged into an online system, its logical file must be placed on logical shutdown status by the damhold command.

To perform maintenance on a DAM file during online operation, the DAM file must be removed from the online system. The damhold and damrm commands must be entered in this order to remove a DAM file from the online system.

The damrles command makes a DAM file that has been placed on logical shutdown status by the damhold command accessible again in the online mode. The damrles command also makes accessible DAM file that has been restored to the online system after error recovery.

The DAM service disables access to a specified file when it accepts the damhold command. An attempt to logically shut down a file subject to deferred updating will fail as it is placed on the logical shutdown waiting status until the blocks in the buffer area corresponding to that file are output onto the disk. Therefore, no logical files can be deleted until the blocks in the buffer area are output onto the disk. In this case, executing the damrm command results in a command error.