Availability Guide for Change Management

Availability Guide for Change Management–125506
7-1
7
Tools for Online Change
Overview
Tandem provides a variety of tools to enable you to make changes to your hardware and
software online. Online change is any change that can be performed while your
NonStop system is still operational. In some situations, online changes may temporarily
affect application availability.
This section describes the features and capabilities of the online change tools referred to
in previous sections of this manual. It does not describe tools provided by companies
other than Tandem. The Software and Services Directory describes third-party products.
You can obtain a copy of the Software and Services Directory from your Tandem
representative.
Subsystem Control Facility (SCF)
SCF is a management application within the Distributed Systems Management (DSM)
architecture. You can use SCF to make changes to your system configuration without
having to take down your system. In the Tandem environment, SCF subsystem is the
name used for software products that provide users with access to a set of
communication services. The communications subsystems that can be changed with
SCF are listed on page 7-3.
SCF Interface
SCF provides a series of commands that operate on objects belonging to each
communications subsystem. Each communications subsystem has its own set of object
types relevant to the subsystem’s configuration and implementation. Some examples of
objects are LINE, PATH, PROCESS, and SU (subdevice).
Using SCF commands, you can:
•
Add, alter, or delete objects (such as devices, I/O processes, and generic processes)
•
Obtain configured or current information about objects
Table 7-1 shows the SCF commands that can be used for online reconfiguration.
(Table 7-1 lists only those commands that are related to online reconfiguration; it does
not list all the SCF commands.)
Note. The system-generation program (SYSGENR) is not discussed in this section because it
is an offline tool (it requires the NonStop system to be stopped). SYSGENR is discussed in
Section 6, “Reducing the Time Required for Planned Outages.”