Task: Alter the parameters that control the number of backup versions kept and how frequently they are eligible for creation. This command cannot be used on SMS-managed data sets, which are controlled by the data sets management class parameters. If the HALTERDS command is used on SMS-managed data sets, the command fails and an error message is issued (see Figure 3).

To make a change, you specify VERSIONS or SYSVERSIONS, FREQUENCY or SYSFREQUENCY, or one from each pair of parameters. If you do not specify at least one with the HALTERDS command, nothing is altered.

RACF® authority: To alter the parameters that affect the backup of a RACF-protected data set, you must have RACF ALTER authority to the data set.

Abbreviation: The minimum abbreviation for the HALTERDS command is HAL.