RETENTION PERIOD field (ARCRETN subsystem parameter)

The ARCRETN subsystem parameter specifies the retention period, which is the number of days that Db2 is to retain archive log data sets. The retention period is added to the current date to calculate the expiration date of the archive log data sets.

Acceptable values: 0–9999
Default: 9999
Update: option 43 on panel DSNTIPB
DSNZPxxx: DSN6ARVP ARCRETN

The retention period is often used in tape management systems to control the reuse and scratching of data sets and tapes. Db2 uses the ARCRETN value as the value for the dynamic allocation parameter DALRETPD when archive log data sets are created.

The retention period set by the DFSMSdfp storage management subsystem (SMS) can be overridden by this Db2 parameter. Typically, the retention period is set to the smaller value that is specified by either Db2 or SMS. The storage administrator and database administrator should agree on a retention period value that is appropriate for Db2.

Important: A wide variety of tape management systems exists, along with the opportunity for external manual overrides of retention periods. Consequently, Db2 does not have an automated method to delete the archive log data sets from the BSDS inventory of archive log data sets. Therefore, the information about an archive log data set might be in the BSDS after its retention period has expired. The information might be held long after the tapes have been scratched by a tape management system. Conversely, the maximum number of archive log data sets might be exceeded (see READ TAPE UNITS field). In such a case, the data from the BSDS might be dropped long before the data set reaches its expiration date.