The chapter addresses the problem of measuring and managing the economics of information storage. By resorting to actual measurements rather than rules of thumb, one can objectively substantiate spending on information storage infrastructure and implementation of specific storage management policies. In the chapter, a versatile model of an information storage system is defined, along with a set of measures pertaining to the respective qualities of information. In addition, aggregate measures are proposed that give an overall view of the information storage system, helping to assess storage management policies with ambivalent results. Finally, the assessment procedure is described.
TopBackground
The very purpose of information storage is to ensure that users:
- 1.
Can store information and
- 2.
Will have access to the very same pieces of information they stored, promptly on their request in the future.
Hence come the three main qualities of information storage (cf. Somasundaram & Shrivastava, 2009, p. 12; Swacha, 2010, p. 112): capacity, performance, and security, here consisting of confidentiality, integrity, and availability (Johnson, 2010, p. 29).
Capacity refers to the ability to store specific volume of information; performance: that access times are acceptable; confidentiality: that information can only be stored and retrieved by those who are permitted to do so; integrity: that every piece of information retrieved is exactly the piece of information that was earlier stored; availability: that information can be retrieved any time it is needed.
Technical measures can be used to assess these qualities in a case of a specific information storage process or system. As the qualities may have various aspects, there is often more than one technical measure of a given quality – e.g., performance can be measured with access time, transfer speed, or number of input-output operations per second (Mendez et al., 2011, p. 479).