Chapter 9. Content-Addressed Storage

In the life cycle of information, data is actively created, accessed, edited, and changed. As data ages, it becomes less likely to change and eventually becomes "fixed" but continues to be accessed by multiple applications and users. This data is called fixed content.

Traditionally, fixed content was not treated as a specialized form of data and was stored using a variety of storage media, ranging from optical disks to tapes to magnetic disks. While these traditional technologies store content, none of them provide all of the unique requirements for storing and accessing fixed content.

Accumulations of fixed content such as documents, e-mail messages, web pages, and digital media throughout an organization have resulted in an unprecedented growth in the amount of data. It has also introduced the challenge of managing fixed content. Furthermore, users demand assurance that stored content has not changed and require an immediate online access to fixed content. These requirements resulted in the development of Content-Addressed Storage (CAS).

CAS is an object-based system that has been purposely built for storing fixed content data. It is designed for secure online storage and retrieval of fixed content. Unlike file-level and block-level data access that use file names and the physical location of data for storage and retrieval, CAS stores user ...

Get Information Storage and Management: Storing, Managing, and Protecting Digital Information now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.