Other options of interest
In most cases, you can reasonably use the VTAM® default values for the APPL statement at first.
You can change these values later. The options are listed below in case you have some reason to not use the default values.
- ACBNAME
- The LU name for the DB2® subsystem. If the ACBNAME is different from the APPL name and both the originating and destination LUs are in the same VTAM domain, do not refer to the ACBNAME in a CDB definition. If the ACBNAME is not the same as the APPL name, VTAM may encounter name conflicts.
- DDRAINL
- Whether the local DB2 subsystem wants to accept permission to drain its allocation requests if a change-number-of-sessions (CNOS) request is received that specifies that draining is allowed. The suggested value is the default, NALLOW (do not allow draining).
- DRESPL
- Whether the local DB2 is responsible for deactivating sessions when it receives a CNOS request specifying the local DB2 as the responsible system. The suggested value is the default, NALLOW (do not be responsible).
- EAS
- The approximate number of concurrent sessions for this DB2 subsystem. For performance reasons, it is better to estimate slightly high. The VTAM default is 509.
- LMDENT
- The number of entries to be used for a hash table of other systems. The suggested value is the approximate number of other systems in the network. In the scenario, Spiffy decides to use the default value of 19.
- MAXPVT
- The maximum additional amount of private area storage that can be used by VTAM within the DDF address space for the session-related control blocks and messages for DB2. Specifying 0 indicates an unbounded amount; this is the VTAM default.
- OPERCNOS
- The ability to have a VTAM operator
display and set VTAM session
limits for a given LUNAME and MODENAME.
- Use ALLOW to enable a VTAM operator to change session limits dynamically without stopping DDF or changing the CONVLIMIT column of the SYSIBM.LUMODES table.
- Use NALLOW, the default, to make sure VTAM operators are not able to dynamically change session limits for DB2.