5.1.1 DIGITAL MIGRATION MOTIVATORS
Three major motivators are seen to drive Digital Migrations of AIPs within an OAIS. These are:
– Improved Cost-Effectiveness: The rapid pace of hardware (e.g., disk/tape drives) and software evolution provides greatly increasing storage capacities and transfer bandwidths at reducing costs. It also drives the obsolescence of some media types well before they have time to decay and it drives the obsolescence of software employed as part of Representation Information. In addition, improved AIP packaging designs may be less dependent on underlying media and supporting systems, and therefore simplified migration efforts may be recognized. To remain cost-effective, an OAIS must take advantage of these technologies. Depending on the particular technologies involved, the AIP information may have to be moved to new media types not previously supported, and it may have to revise its AIP implementations to maintain information preservation.
– New Consumer-Service Requirements: The Consumers of an OAIS also experience the benefits of new technologies and consequently raise their expectations of the types and levels of service they expect from an OAIS. These increased services may require new forms of DIPs to service particular Designated Communities, which in turn may drive an OAIS to hold new forms of AIPs to reduce output conversions. Additionally, AIPs typically go through popularity swings and the OAIS may need to provide different levels of access performance to meet Consumer demands over time. This is likely to be satisfied by moving some AIPs to different media that provide increased or decreased levels of access performance. Finally, the Designated Community for a given AIP may be broadened, resulting in the need to revise AIP forms so as to be understandable and usable by this broader community. All of these can result in the migration of AIPs within an OAIS.
– Media Decay: Digital media, over time, become increasingly unreliable as secure preservers of bits. Even those that are used with some level of error correction eventually need to be replaced. The net result of media decay is that AIP information must be moved to newer media.
Digital Migrations are time consuming, costly, and expose the OAIS to greatly increased probabilities of information loss. Therefore, an OAIS has a strong incentive to consider Digital Migration issues and approaches.
--Please retain original text above for reference. Propose amendments or additions below this line or respond using the Discussion tab above--
These wiki pages are licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. Attribute as "Community forum for digital preservation and curation standards http://wiki.dpconline.org/". The content on this wiki represents the opinions of the author and not the Digital Preservation Coalition. This wiki is not associated with ISO, the OAIS Standard or the CCSDS.