Digital Data Preservation Digital Data Preservation Research into a solution for preservation of digital Research into a solution for preservation of digital information information Barry M. Lunt, Ph.D.; Professor, Information Barry M. Lunt, Ph.D.; Professor, Information Technology, BYU Technology, BYU Matthew R. Linford Linford, Ph.D.; Associate Professor, , Ph.D.; Associate Professor, Matthew R. Chemistry & Biochemistry, BYU Chemistry & Biochemistry, BYU Feng Zhang, Ph.D. student; Chemistry & Biochemistry Zhang, Ph.D. student; Chemistry & Biochemistry Feng Ryan Sydenham Sydenham, B.S student; Mechanical Engineering , B.S student; Mechanical Engineering Ryan Mar 15, 2007 Family History Technology 1 Mar 15, 2007 Family History Technology 1
Presentation Outline Presentation Outline � Defining the Problem Defining the Problem � � Evidences of the Problem Evidences of the Problem � � Stimuli toward Research Stimuli toward Research � � Existing Optical Storage Existing Optical Storage � � Research Progress Research Progress � � Conclusion Conclusion � Mar 15, 2007 Family History Technology 2 Mar 15, 2007 Family History Technology 2
Defining the Problem Defining the Problem � All current methods of storing digital information All current methods of storing digital information � are ephemeral, by historical standards: are ephemeral, by historical standards: � Magnetic: 30 Magnetic: 30 – – 50 years 50 years � � Optical (recordable): 7 Optical (recordable): 7 – – 23 years 23 years � � Solid state (Flash memory): 10 Solid state (Flash memory): 10 – – 12 years 12 years � � Much modern information has no analog Much modern information has no analog � counterpart counterpart � Digital information does not gracefully degrade Digital information does not gracefully degrade � Mar 15, 2007 Family History Technology 3 Mar 15, 2007 Family History Technology 3
Evidences: Evidences: “Longevity of CD Media Longevity of CD Media” ” – – Research at the Research at the “ Library of Congress Library of Congress � 125 CDs, randomly selected from 60,000 collection 125 CDs, randomly selected from 60,000 collection � All CDs experience the same conditions (normal storage and circulation) Mar 15, 2007 Family History Technology 4 Mar 15, 2007 Family History Technology 4
Evidences: Evidences: “Longevity of CD Media Longevity of CD Media” ” – – Library of Congress Library of Congress “ Accelerated aging test Accelerated aging test Mar 15, 2007 Family History Technology 5 Mar 15, 2007 Family History Technology 5
Evidences: Evidences: “Longevity of CD Media Longevity of CD Media” ” – – Library of Congress Library of Congress “ Accelerated aging test Accelerated aging test Mar 15, 2007 Family History Technology 6 Mar 15, 2007 Family History Technology 6
Evidences: Evidences: NIST – – Accelerated aging test, CD Accelerated aging test, CD- -Rs Rs NIST Mar 15, 2007 Family History Technology 7 Mar 15, 2007 Family History Technology 7
Evidences: Evidences: NIST – – Accelerated aging test, CD Accelerated aging test, CD- -Rs Rs NIST Mar 15, 2007 Family History Technology 8 Mar 15, 2007 Family History Technology 8
Evidences: Fred Byers (NIST): Fred Byers (NIST): Evidences: Accelerated aging test, CD- -Rs Rs Accelerated aging test, CD Projected Time to Failure: 14.75 years; 23.09 Projected Time to Failure: 14.75 years; 23.09 years years Mar 15, 2007 Family History Technology 9 Mar 15, 2007 Family History Technology 9
Evidences: Evidences: International Journal for the Preservation International Journal for the Preservation of Library and Archival Material of Library and Archival Material The Relative Stabilities of Optical Disc Formats The Relative Stabilities of Optical Disc Formats Mar 15, 2007 Family History Technology 10 Mar 15, 2007 Family History Technology 10
Mar 15, 2007 Family History Technology 11 Mar 15, 2007 Family History Technology 11
Computerworld Stimuli: Computerworld Stimuli: � www.computerworld.com/blogs/note/625 www.computerworld.com/blogs/note/625 � � Marian Marian Prokop Prokop, 7/22/05 , 7/22/05 � “Federal employees involved in preservation and Federal employees involved in preservation and “ archiving want the optical disks they use to have a archiving want the optical disks they use to have a lifespan of at least 40 years, according to a survey. lifespan of at least 40 years, according to a survey. The Government Information Preservation The Government Information Preservation Working Group is working the National Institute Working Group is working the National Institute of Standards and Technology to establish a long- - of Standards and Technology to establish a long term, or archival, standard measurement for term, or archival, standard measurement for recordable CD and DVD media.” ” recordable CD and DVD media. Mar 15, 2007 Family History Technology 12 Mar 15, 2007 Family History Technology 12
Digital Documents Stimuli: Digital Documents Stimuli: � Digital photos Digital photos � � Digital videos Digital videos � � Computer software Computer software � � Computer models Computer models � � Blogs Blogs � � Other personal websites Other personal websites � Mar 15, 2007 Family History Technology 13 Mar 15, 2007 Family History Technology 13
Stimulus Stimulus � “ “Predicting the Life Expectancy of Modern Predicting the Life Expectancy of Modern � Tape and Optical Media” ” Tape and Optical Media (Vivek Vivek Navale Navale, National Archives and Records , National Archives and Records ( Administration; Aug 15, 2005, Vol Vol 9, #4) 9, #4) Administration; Aug 15, 2005, “[The study] shows the probability of failure as a [The study] shows the probability of failure as a “ function of time at 25° °C and 50% RH. It predicts a C and 50% RH. It predicts a function of time at 25 mean life time of 1592 years 1592 years for CD for CD- -ROMS ROMS mean life time of stored under those conditions.” ” stored under those conditions. Mar 15, 2007 Family History Technology 14 Mar 15, 2007 Family History Technology 14
• Recording technologies Recording technologies • • Comparison of CD, DVD, BRD • Comparison of CD, DVD, BRD • Stamped Stamped • • ROM (writeable) ROM (writeable) – – dye dye- -based based • • R/W (re R/W (re- -writeable) writeable) – – phase phase- -change change • • R/W (re R/W (re- -writeable) writeable) – – magneto magneto- -optical optical • Mar 15, 2007 Family History Technology 15 Mar 15, 2007 Family History Technology 15
Technology Migration Mar 15, 2007 Family History Technology 16 Mar 15, 2007 Family History Technology 16
SEM of Stamped CD Mar 15, 2007 Family History Technology 17 Mar 15, 2007 Family History Technology 17
SEM of CD-R Mar 15, 2007 Family History Technology 18 Mar 15, 2007 Family History Technology 18
Confocal image of CD-R Mar 15, 2007 Family History Technology 19 Mar 15, 2007 Family History Technology 19
Recordable Optical Discs - Use Groove tracking for “Writing” function. Pit-like Gratings for the “Reading” function. - Works primarily through the use of cyanine dyes that absorb energy and create a pit-like structures that act as Amplitude Gratings. Mar 15, 2007 Family History Technology 20 Mar 15, 2007 Family History Technology 20 Courtesy of Mark Worthington
REWRITABLE OPTICAL DISCS -RW technologies use phase change materials. Active layer (metallic stack) changes states when exposed to pulsed low energy level. Returns to reflective state when exposed to higher energy level. (crystal/amorphous) Mar 15, 2007 Family History Technology 21 Mar 15, 2007 Family History Technology 21 Courtesy of Mark Worthington
Magneto- -Optical Technology Optical Technology Magneto � Based on Curie point of magnetic materials Based on Curie point of magnetic materials � � Uses: Uses: � � Laser to heat material to near Curie point Laser to heat material to near Curie point � � Magnetic field to change magnetization Magnetic field to change magnetization � � Kerr effect in read Kerr effect in read- -back back � � Features: Features: � � Magnetic domain as small as spot size of laser Magnetic domain as small as spot size of laser � � Nearly infinite R/W cycles Nearly infinite R/W cycles � Mar 15, 2007 Family History Technology 22 Mar 15, 2007 Family History Technology 22
Research Progress to Date Research Progress to Date � Research on stability and adhesion of metal Research on stability and adhesion of metal � films films � Tape test for adhesion Tape test for adhesion � � Boil test for stability Boil test for stability � � Research on size and optical properties of Research on size and optical properties of � recorded bits recorded bits � Protective layer for recording Protective layer for recording � Mar 15, 2007 Family History Technology 23 Mar 15, 2007 Family History Technology 23
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