Cloud Management - Deploying and Managing a Cloud Infrastructure - page 107

The essence of configuration management is the trust it puts in the CMS and the own-
ers of the CIs. That trust may also be a drawback, but it can be used as an indicator for the
success of the configuration management process. It assumes that all information is accu-
rate and updated and no longer needs to be investigated. If any change activity undermines
the trust, then an investigation is necessary to rediscover CI attributes, relationships, and
current statuses. In such a case, the value of control, cost and time savings are in fact lost,
which configuration management was meant to achieve.
The following sections describe some main concepts you need to understand in order to
fully grasp configuration management.
Configuration Management Database (CMDB)
As the name suggests, a configuration management database is the data repository used for
configuration management in IT organizations. It is intended to hold configuration items
(CIs) for various IT assets. For each CI, it includes information like settings, software and
firmware versions, and the owners of the CI as well as the relationships it has with other
assets around it, like upstream sources, downstream targets, and the various dependencies
and interfaces. This can be broken down into three categories of data: technical, ownership,
and relationship, which are all self-explanatory.
The CMDB is used to document and track the state of various IT assets arranged into con-
figuration items. These are usually products, facilities, systems, individual devices like servers
or a set of devices like a local area network or server farm, software, and even people. The
CMDB can contain images that give insight into specific assets at a certain state. The images
can then be used to restore or reconstruct assets to a specific state at any point of its existence.
For example, if there was a change in network settings and it didn't work, the network could
simply be restored based on the information contained in the CI for the network, taken from
the CMDB. It can also be used for impact analysis and root-cause analysis.
The Information Technology Infrastructure Library (ITIL) framework describes the
CMDB as an integral part of infrastructure operations and support and therefore the CMDB
servers as the authorized and official configuration of the significant components of an IT
environment. It helps the organization better understand the relationships. It is a fundamental
component of ITIL's configuration management process, and its implementation involves the
federation and inclusion of data from other sources, such as asset management, in a way in
which the source may retain control of the data.
Managing Capacity
Capacity management is the process of ensuring that the current and future performance
and capacity demands of customers and end users and other services are delivered with
acceptable costs. Its main purpose is to ensure that there is enough IT capacity to meet
customer demands and fulfill service-level agreements.
Capacity management is dependent on configuration management because it involves
reliability and optimization, so the emphasis should be on meticulous detail and proper