Fixity Architecting for Integrity

Fixity Architecting for Integrity. Scott Rife, Library of Congress, presentation. Designing Storage Architectures for Digital Collections 2015. September 2015. [PDF]
     The Problem: “This is an Archive. We can’t afford to lose anything!” They are custodians to the history of the United States and do not want to consider that the loss of data is likely to happen. The current solutions:

• At least 2 copies of everything digital
• Test and monitor for failures or errors
• Refresh the damaged copy from the good copy
• This process must be as automated as possible
• Recognize that someday data loss will occur

Fixity is the process of verifying that a digital object has not been altered or corrupted. It is a function of the whole architecture of Archive/Long Term Storage (hardware, software, network, processes, people, budget)
What costs are reasonable to reduce the loss of data?
Need to understand the possible solutions.  How much more secure will our customers content be if:

• There is a third, fourth or fifth copy?
• All content is verified once a year versus every 5 years?
• More money is spent on higher quality storage?
• More staff are hired

RAID, erasure encoding, is at risk due to larger disk sizes. With storage, there is a wide variation in price, performance and reliability. Performance and reliability are not always correlated with price. Choose hardware combinations to limit likely failures based on your duty cycle

Digital Preservation Matters.