Tales from “THE disK FILES”: Lessons Learnt from a Data Recovery Project in 2003–2006 at the National Archives of Australia

Abstract

This case study re-evaluates a large-scale project carried out by the National Archives of Australia (NAA) between 2003 and 2006. The project aimed to identify obsolete digital media (physical data carriers) in its collection and to describe and recover the data from the carriers using a third-party data recovery provider.1 A detailed process for data recovery was developed that included the capture of a full audit trail of steps in the data recovery process. The project was completed in four stages: phase 1 obtained bit-level images from the carriers; phase 2 extracted individual bit-files from the carriers; phase 3 identified duplicate files and proprietary or complex file formats; and phase 4 was a final report that documented processes, made recommendations on future processes, and provided lessons learned. Recent work described in this article indicates that files extracted from the carriers in 2004–2005 can be accurately rendered in current computer environments. The ongoing significance of the project is that it is an early demonstration of the success of bit-level preservation and the need to create disk images as part of a preservation workflow, suggesting a sustainable methodology for digital preservation. The project also influenced archival policy at the NAA and influenced the development of subsequent software tools that became widely known in the broader digital preservation community. The focus on archival principles of authenticity, integrity, chain of custody, and provenance of the recovered records were key learnings to ensuring long-term access and usability. Finally, the metrics resulting from the project, for example, rates of readable carriers and rates of data recovery by carrier type, are useful data from a point in time that correspond quite closely to similar data recovery projects undertaken by other institutions at about the same time and provide a benchmark for future research.