Emulation as a Strategy for Digital Preservation
Twenty years ago, Jeff Rothenberg’s seminal “Ensuring the Longevity of Digital Documents” compared migration and emulation as strategies for digital preservation, strongly favoring emulation. Emulation was already a long-established technology; as Rothenberg wrote Apple was using it as the basis for their transition from the Motorola 68K to the PowerPC. Despite this, the strategy of almost all digital preservation systems since has been migration. Why was this?
Preservation systems using emulation have recently been deployed for public use by the Internet Archive and the Rhizome Project, and for restricted use by the Olive Archive at Carnegie-Mellon and others. What are the advantages and limitations of current emulation technology, and what are the barriers to more general adoption?
David S. H. Rosenthal invented the LOCKSS (Lots Of Copies Keep Stuff Safe) technology and has been chief scientist of the LOCKSS program at the Stanford Libraries since it started more 17 years ago. The program develops tools that allow libraries to collect and preserve web published materials (e-journals, books, blogs, web sites, archival materials, etc) using low-cost, collaborative, peer-to-peer technology. Dr. Rosenthal is a long-time Silicon Valley engineer. He was an early employee at Sun Microsystems, where he helped developed the X Window System which has long been the open source standard. He was employee #4 at Nvidia, now the leading supplier of high-performance graphics chip.