By Lance Hickerson, Reference Department
“Today, the average household creates enough data to fill 65 iPhones (32gb) per year. In 2020, this will grow to 318 iPhones.”
This is a conclusion from the seventh EMC Digital Universe study at Hopkinton, Massachusetts highlighting a special concern with how “data is outpacing storage. The world’s amount of available storage capacity (i.e., unused bytes) across all media types is growing slower than the digital universe.”
Concerns about digital storage and preservation are not new, but they are now more pressing. Michael Irving, of New Atlas, explains how “even the best of our current range of devices are only relatively short-term solutions to the problem. Hard drives, and optical storage such as DVDs and Blu-Ray discs, are vulnerable to damage and degradation, with a life expectancy of a few decades at best.” Irving continues:
Scientists are increasingly looking to nature’s hard drive, DNA, as a potential solution to both the capacity and longevity problems. As our own bodies demonstrate, DNA is an incredibly dense storage medium, potentially squeezing in a mind-boggling 5.5 petabits (125,000 GB) of information per cubic millimeter. By that measure, according to University of Washington professor, Luis Ceze, all 700 exabytes of today’s accessible internet would fit into a space the size of a shoebox. You could then tuck that shoebox away in a vault for thousands of years, and the DNA-stored data would remain intact.
Indeed, digital storage modeled on DNA is a promising solution. But until it becomes more than experimental, what should we do in the meantime? For instance, what if you have just been chosen as the archivist for a massive collection of family photographs? How would you choose to store the data? In addition to preserving the actual physical photos, what is the best approach from a digital point of view? After the photos are scanned, what is the best way to store them as digital documents?
A helpful answer comes from Denise May Levenick, who inherited her family photo treasures. She shares tips and techniques for preserving a collection in her latest book, How to Archive Family Photos: A step by step guide to organize and share your photos digitally (Family Tree Books: Cincinatti, 2015. In our library nonfiction section under 745.593 May). It is good to keep in mind that, although focusing on photos, the principles she outlines apply to more than photo collections.
One important decision for digital material concerns negotiating different file formats. Ms. Levenich explains about using JPG and TIFF files.
JPG is a file format that uses compression when saving files and is called a lossy file format because repeated opening and saving of JPG files deteriorates the image quality over time. TIFF is a file format that does not use compression when saving files and is considered a lossless format because it maintains its quality over time.
What this means for preservation is that the TIFF lossless format better maintains the digital data than the JPG format, which loses quality with use. One concern with TIFF files, however, is that TIFF is sometimes unreadable by various programs. In this case, our staff librarian photo buff, Rebecca Tischler, recommends saving picture files in PNG. PNG, pronounced “ping,” stands for the Portable Network Graphics format which compresses information in a lossless manner, meaning all the image information is there when the PNG file is decompressed. Further it neither degrades nor loses information with saving, restoring, or resaving like the JPG. Don’t count out the JPG, however, as it has its uses too, one being the JPG can preserve a lot more color than the PNG.
Once your format is chosen, it is necessary to back up your photo files. Ms. Levenick recommends the 3-2-1 rule.
- 3 Copies
- 2 different media
- 1 copy stored off-site
She explains, “Many different combinations will provide a good backup solution, but the key to a great backup system is to spread out your copies across different media and different storage locations. When hurricanes and tornadoes wipe out a home and family photo collection, it’s reassuring to know that digital copies are safe in the cloud, or stashed at a relative’s home in another state. Don’t wait for a disaster to safeguard your precious family memories. Practice the 3-2-1 Backup rule regularly, especially after a major scanning session.”
- Michael Irving, “New record for storing digital data in DNA” in New Atlas (July 11, 2016)
- Denise May Levenick, How to Archive Family Photos: A step by step guide to organize and share your photos digitally (Family Tree Books: Cincinatti, 2015), pp. 108-109; 126.
- The Data Deluge: An e-Science Perspective, Tony Hey*(Tony.Hey@epsrc.ac.uk) + and Anne Trefethen*(Anne.Trefethen@epsrc.ac.uk),UK e-Science Core Programme