Availability Guide for Change Management

Introduction to Change Management
Availability Guide for Change Management–125506
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Controlling the Introduction of Change
Evaluating System Performance and Growth
Evaluating system performance and growth involves tracking and anticipating growth
and then establishing plans to accommodate that growth. Tandem provides a wide
variety of tools that provide data useful for your growth forecasts. These tools, and
performance-management tasks, are described in the Introduction to NonStop
Operations Management.
Providing Adequate Computer Room Resources
Some changes, such as adding new hardware, can require more power and air
conditioning. You can avoid unnecessary downtime by providing adequate physical
space and ensuring that you have enough power and cooling capacity for additional
equipment. Assessing resource requirements is described in Section 2, “Change
Control.”
Configuring Your System With Change in Mind
Some changes can be performed online only if you have designed your system
configuration to accommodate them ahead of time. Section 3, “Making System
Software and Hardware Changes Online,” describes how you can avoid taking your
system down to add new hardware. Anticipating and planning for change are discussed
in Section 6, “Reducing the Time Required for Planned Outages.”
Controlling the Introduction of Change
Regardless of the type of change you need to make, you should establish and use a
formal change-control process to ensure that changes proceed smoothly and with
minimal impact on system and application availability.
Change control is a process for proposing, planning, implementing, and testing change
and is a key requirement for minimizing the impact of change on system and application
availability. Change control is also an important part of maintaining the security of your
system and applications.
Section 2, “Change Control,” describes and recommends a four-phase change-control
process to help you ensure that changes are implemented successfully and with minimal
impact on system and application availability.
Installing and Implementing Changes
Installing and implementing changes to your NonStop system can involve:
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Installing a new operating system release
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Installing an Interim Product Modification (IPM)
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Adding, removing, and reconfiguring hardware
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Installing and reconfiguring application subsystems
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Installing and reconfiguring communications subsystems
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Installing and reconfiguring applications