.-DLRTCB--=--32----------------------------. >>-+------------------------------------------+---------------->< '-DLRTCB--=--number_of_task_control_blocks-'
| range: | 1–32767 |
- Dump-Load-Restart
- File I/O services
- Cryptographic services
- Configuration checkpoint services
- WTOR message services
The DLRTCB start option is closely related to the MAXHNRES start option. The MAXHNRES start option controls the number of subtasks that VTAM allows for Enterprise Extender host name resolution requests. The MAXHNRES start option value is internally added to the value of the DLRTCB start option value, but the value cannot exceed the DLRTCB upper limit.
Restriction: The DLRTCB and MAXHNRES start options cause control blocks to be built below the 16-megabyte line. Therefore, the availability of storage might limit the value that you can code, and conversely, the value that you code might impact the availability of the storage. Also, if several dump-load-restart subtasks are active at the same time, the value that you code for this start option might affect performance. A value that is too low can cause VTAM initialization to stall or suspend a session initiation for a function that requires a TCB until a TCB becomes available
- If VTAM is initialized as an APPN network node (NODETYPE=NN) and you specify a value less than 5 for the DLRTCB start option, then the value for DLRTCB is set to 5. Two TCBs are needed to process APPN directory services data sets and topology and routing services data sets, and at least three TCBs are needed for other dump-load-restart functions. If VTAM is initialized as a pure subarea node (NODETYPE start option not specified) and you specify a value less than 3 for the DLRTCB start option, then the value for DLRTCB is set to 3.
- No more than 2 TCBs will be used for cryptographic processing.
- Issuing a D NET, VTAMOPTS command displays the specified DLRTCB value; it does not display the combined DLRTCB and MAXHNRES value.