Overview

In 2020, Digital Preservation Services (DPS) began working with units to explore incorporating alternate preservation storage targets. Currently the primary use case for alternate storage are preservation copies of audiovisual objects, which tend to be the largest files and therefore, the most expensive. The University of Southern California's (USC) Digital Repository employs a cost model that is charged over a 20-year increment and is lower than the current costs of DRS archival class storage. DPS helps broker usage and develop deposit workflows for Harvard units interested in leveraging this option. As of December 2022, one Harvard unit is actively utilizing USC for preservation storage and another is evaluating it for their current digitization project.

Cost comparison

Harvard's Digital Repository Service (DRS) is a charge-back cost model, with archival files being billed at $0.55/GB/year. The USC Digital Repository's cost model is charged back at a rate of $800/TB/20 years. Since the models vary, the below table demonstrates the prices for a unit that planned to regularly deposit 1 TB of content every year for 20 years and accrued a total of 20 TB at the end of 20 years.

Sample costs over 20 years, Harvard DRS and USC Digital Repository

*The price drop for Harvard DRS in 2022-2023 is the result from a storage refresh that significantly reduced costs. Because this table projects costs over 20 years, future cost reductions for the Harvard DRS cannot otherwise be predicted, so all remaining fiscal years represented in the table are based on the current archival storage class cost of $0.55/GB/year.

	Library deposits, in TB				Harvard DRS	USC Digital Repository
FY	FY ingest		Total to date		Total FY cost	Ingest cost	Total FY cost	% of DRS	Annualized	% of DRS
2020-2021	1	TB	1	TB	$ 1,250	$ 800	$ 800	64.0%	$ 40	3.2%
2021-2022	1	TB	2	TB	$ 2,500	$ 800	$ 800	32.0%	$ 80	3.2%
2022-2023	1	TB	3	TB	$ 1,650	$ 800	$ 800	48.5%	$ 120	7.3%
2023-2024	1	TB	4	TB	$ 2,200	$ 800	$ 800	36.4%	$ 160	7.3%
2024-2025	1	TB	5	TB	$ 2,750	$ 800	$ 800	29.1%	$ 200	7.3%
2025-2026	1	TB	6	TB	$ 3,300	$ 800	$ 800	24.2%	$ 240	7.3%
2026-2027	1	TB	7	TB	$ 3,850	$ 800	$ 800	20.8%	$ 280	7.3%
2027-2028	1	TB	8	TB	$ 4,400	$ 800	$ 800	18.2%	$ 320	7.3%
2028-2029	1	TB	9	TB	$ 4,950	$ 800	$ 800	16.2%	$ 360	7.3%
2029-2030	1	TB	10	TB	$ 5,500	$ 800	$ 800	14.5%	$ 400	7.3%
2030-2031	1	TB	11	TB	$ 6,050	$ 800	$ 800	13.2%	$ 440	7.3%
2031-2032	1	TB	12	TB	$ 6,600	$ 800	$ 800	12.1%	$ 480	7.3%
2032-2033	1	TB	13	TB	$ 7,150	$ 800	$ 800	11.2%	$ 520	7.3%
2033-2034	1	TB	14	TB	$ 7,700	$ 800	$ 800	10.4%	$ 560	7.3%
2040-2035	1	TB	15	TB	$ 8,250	$ 800	$ 800	9.7%	$ 600	7.3%
2035-2036	1	TB	16	TB	$ 8,800	$ 800	$ 800	9.1%	$ 640	7.3%
2036-2037	1	TB	17	TB	$ 9,350	$ 800	$ 800	8.6%	$ 680	7.3%
2037-2038	1	TB	18	TB	$ 9,900	$ 800	$ 800	8.1%	$ 720	7.3%
2038-2039	1	TB	19	TB	$ 10,450	$ 800	$ 800	7.7%	$ 760	7.3%
2039-2040	1	TB	20	TB	$ 11,000	$ 800	$ 800	7.3%	$ 800	7.3%
TOTAL FOR 20 YEARS	20	TB	20	TB	$ 117,600	$ 16,000	$ 16,000	13.6%	$ 8,400	7.1%

Pilot projects

Judaica

In early 2020, the Judaica division finalized an agreement to deposit the archival copies of their audiovisual assets in the USC Digital Repository and continue to use Harvard's DRS for access copies.

Divinity

As part of their mass audiovisual digitization project, the Divinity School Library is evaluating the USC Digital Repository as a potential solution for storing the archival copies.

Learn more

If you are interested in potentially leveraging USC preservation storage, please contact Stephen Abrams, Head of Digital Preservation Services.

Harvard Library Digital Preservation

USC Digital Repository storage

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