This paper tackles an important topic. Nowadays, many of our activities rely on resources stored in digital format. The rapid obsolescence of computer environments, due to advances in both hardware and software, makes the preservation of digital data a challenge. This, along with the growing complexity and size of the data that must be stored--for example, a resource may consist of several interrelated files with different formats--emphasizes the importance of designing solutions to ensure automatic preservation of the data.

Hedges et al. consider the use of a data grid as the basis for a preservation environment. In particular, they advocate a rule-based approach, implemented on the integrated rule-oriented data system (iRODS), to perform format normalization and migration of digital objects. Two example scenarios show the use of iRODS rules to implement curation and preservation strategies: in one of the scenarios, a digital resource is ingested into the preservation environment; in the other, periodic actions are automatically executed to ensure the integrity and format accessibility of the digital resources in the archive.

This paper, an extension of the authors’ earlier work [1], provides an interesting overview of an approach that can be used to perpetuate our digital data. It succeeds in motivating the problem and highlighting the difficulties involved--for example, the need to define a workflow chain and recovery strategies. It is very readable and appropriate for anyone who is interested in the topic, but a lot of work remains to be done to solve this difficult issue.