Tuesday, December 20, 2016

File Extensions and Digital Preservation

File Extensions and Digital Preservation. Laura Schroffel. In  Metadata Specialists Share Their Challenges, Defeats, and Triumphs. Marissa Clifford. The Iris. October 17, 2016
     The post looks at metadata challenges with digital preservation. Most of the born-digital material they work with exists on outdated or quickly obsolescing media, such as floppy disks, compact discs, hard drives, and flash drives that are transferred into their Rosetta digital preservation repository, and accessible through Primo.

"File extensions are a key piece of metadata in born-digital materials that can either elucidate or complicate the digital preservation process". The extensions describe format type, provide clues to file content, and indicate a file that may need preservation work. The extension is an external label that is human readable, often referred to as external signatures. "This is in contrast to internal signatures, a byte sequence modelled by patterns in a byte stream, the values of the bytes themselves, and any positioning relative to a file."

Their born-digital files are processed on a Forensic Recovery of Evidence Device ( FRED) which can acquire data from many types of media, such as Blu-Ray, CD-ROM, DVD-ROM, Compact Flash, Micro Drives, Smart Media, Memory Stick, Memory Stick Pro, xD Cards, Secure Digital Media and Multimedia Cards. The workstation also has the Forensic Toolkit (FTK) software is capable of processing a file and can indicate the file format type and often the software version. There are challenges since file extensions are not standardized or unique, such as naming conflicts between types of software, or older Macintosh systems that did not require files extensions. Also, because FRED and FTK originated in  law enforcement, challenges arise when using it to work with cultural heritage objects.

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