Dynamic reconfiguration and change of operands

Dynamic reconfiguration is the process of adding, deleting, or moving resources within your network configuration without deactivating the affected major node. For example, you can change resources on an NCP without deactivating the NCP. Dynamic reconfiguration does not replace NCP generations, but supplements them to enable quick and efficient control of changes in the domain configuration. You can also use dynamic reconfiguration for local peripheral nodes, Enterprise Extender XCA major nodes, application major nodes, and CDRSC major nodes.

Dynamic change of operands enables you to modify certain operand values on resource definition statements without deactivating the major node.

Tip: LUs and PUs can be defined dynamically, in which case no system definition is required.
Dynamic reconfiguration and dynamic change of operands are supported for the following resources:
  • PUs and LUs on nonswitched SDLC lines or ESCON channels in an NCP major node
  • PUs, LUs, and PATHs can be added and deleted in a switched major node
  • LUs in a local SNA major node
  • Type 1 PUs under NCP frame-relay lines, and their associated FRSESET definition statements
  • TRLEs in a TRL major node
  • GROUP definitions, LINE definitions, and PORT connection network definitions in an Enterprise Extender XCA major node
  • CDRSCs in a CDRSC major node
  • APPL definitions in an APPL major node
Dynamic change of operands is also supported for PUs and LUs in switched major nodes.
Dynamic reconfiguration of NCP resources requires NCP Version 4 Release 3 or Version 5 Release 3, or later (unless noted) and allows you to:
  • Add and delete type 1, type 2, and type 2.1 physical units and their associated logical units on nonswitched SDLC lines
  • Add and delete logical units under physical units on nonswitched SDLC lines
  • Add and delete type 2.1 physical units on an NCP ESCON channel
  • Add and delete independent logical units on an NCP ESCON channel
    Note: Independent LUs can be dynamically defined, in which case no system definition of the independent LU is required. Independent LUs can also be defined using CDRSC definition statements.
  • Add and delete NCP frame-relay type 1 PUs and their associated FRSESET definition statements
  • Move a physical unit and its associated logical units from its current line to another line within the same NCP
  • Code and change the values of the following NCP operands in the NCP and switched major nodes:
    • COMRATE
    • DLCI
    • DYNWIND
    • HPRQLIM
    • INTFACE
    • IPQLIM
    • LADDR
    • T1TIMER
    • T2TIMER

    The values you specify for these NCP operands are passed to NCP during dynamic reconfiguration of the NCP or during switched PU connection.

    Note that VTAM® registers only the values of these operands and does minimal validation of them before passing them to NCP. For more information about these operands, see the NCP, SSP, and EP Resource Definition Reference.

  • Move a logical unit to another physical unit on nonswitched SDLC lines.
  • Change the ADDR for a physical unit on nonswitched SDLC lines.
  • Change the LOCADDR for a logical unit on nonswitched SDLC lines.
  • Add TRLE entries to a TRL major node or replace existing TRLE entries that are not currently in use (that is, a TRLE entry that is currently in use is not deleted; new entries are still added). A TRLE entry that exists in another TRL major node is not replaced whether it is in use.
There are several ways to perform dynamic reconfiguration. See Dynamic reconfiguration and dynamic change requirements to determine which method is valid for a given resource:
  • Add, delete, or move resources in the VTAMLST definition file and issue a VARY ACT,UPDATE=ALL command. Changes made in this way are permanent changes, and do not require the major node to be deactivated.

    See Using the VARY ACT,UPDATE technique for additional information.

  • Code a DR file to add, delete, and move resources and activate it with the VARY DRDS command. Changes made in this way are temporary changes. If you want the changes to be permanent, a new NCP must be generated and reloaded to reflect the changes as soon as time permits.

    See Using the VARY DRDS technique for additional information.

  • Use the MODIFY DR command to move or delete resources. Changes made in this way are temporary changes. If you want the changes to be permanent, a new NCP must be generated and reloaded to reflect the changes as soon as time permits.

    See Using the MODIFY DR technique for additional information.

  • Add resources to the NCP VTAMLST definition file, and then reactivate the NCP (implicit dynamic reconfiguration). This procedure is disruptive because deactivation of an NCP causes all existing sessions to be terminated. As soon as possible, you must regenerate and reload the NCP to reflect the changes.

    See Implicit dynamic reconfiguration for additional information.

For some examples of dynamic reconfiguration, see Dynamic reconfiguration examples.

Parent topic: Defining resources dynamically