Table of Contents

Overview

The Digital Repository Service (DRS) is the Harvard Library’s centrally-supported programmatic solution for long-term preservation of the University’s digital resources. For purposes of effective and affordable curatorial and operational management, the DRS supports dynamic disposition of all managed digital files to various storage locations according to the storage classification, as designated by a curator.

One of the primary preservation strategies of the DRS is reliance upon geographically-dispersed storage replication across heterogenous storage media to minimize opportunities for single points of failure. Files are dispositioned across different storage locations according to a policy designed to ensure that at least one full copy of all managed files is in online, on-premises storage and another one on off-site tape. Additional replicas and locations provide added-value preservation assurance.

Storage classes

The DRS supports six (6) distinct DRS storage classes: Sensitive, Repurposable, Deliverable, Data, Basic, Large, and Archival. The central concept of the new infrastructure is that content should be hosted on storage platforms that best match their curatorial designation (see the Table below). Upon deposit of content into the DRS, files will be automatically assigned a storage class based on file roles and deliverable logic, but curators can also manually designate the appropriate storage class for the content. Please visit the LTS wiki documentation for more information on Assigning Storage Classes and Editing Metadata and Storage Classes. The Digital Preservation Services team is available for consultation on the selection of storage classes.

Storage class name	Description	Examples of appropriate content	Number of copies	Cost/GB
Sensitive (SE)	Intended for content that is considered Level 4 high-risk confidential information (HRCI)	Email with personal identifying information (PII) Disk images that include portions of unknown data that might include PII	4	$0.70
Repurposable (RE)	Intended for content that requires archival persistence as well as patron use - one of two classes that can be used for files that need to be discoverable	Still images in JPEG2000 that are meant as both the preservation and deliverable copy	5	$0.90
Deliverable (DE)	Intended for content meant for patron use - one of two classes that can be used for files that need to be discoverable	Page-turned images and OCR MP3 files deposited for streaming on a delivery platform	4	$0.85
Basic (BA)	Intended for content that is either lower-value or lower-risk and requires only basic-level service	Digitized book that is also stored by other organizations (like HathiTrust)	3	$0.55
Large (LG)	Intended for individual files that are 5GB or larger in size	Archival MPEG-4 video file Genomic sequence file	3	$0.55
Archival (AR)	Intended for files that require archival persistence	High-resolution still images in an uncompressed TIFF format High-fidelity WAVE audio	4	$0.60

Many classifications can be mapped from long-standing content characteristics and DRS metadata. For example, sensitive data contributed to the DRS from the EAS (Email Archiving System) would naturally be assigned to the Sensitive class. Large files can be assigned to the Large class based on their size. Deliverable material, i.e., that having Public (P) or Restricted (R) access and an associated delivery service URN, would be assigned to the Deliverable class.

Note, however, that any files necessary for delivery service function (IDS, PDS, SDS) must be assigned to either the Deliverable (DE) or Repurposable (RE) classes in order to be visible to the services. This includes primary files, e.g., streamable audio and video, PDS objects, as well as ancillary files, e.g., audio playlists, video closed captioning, individual PDS page images, etc.

Storage cost calculator

Use this storage calculator to estimate storage costs in the DRS. For each storage class, enter the size of the deposit in gigabytes (GB). You can additionally select the number of years over which you would like to project costs. The calculator will summarize total costs as well as the quarterly fiscal year (FY) charge.

Frequently Asked Questions

When does billing occur and how are units charged?

DRS depositors are charged for the amount of storage space their content utilizes annually. Billing for these charges occurs on a quarterly basis throughout the fiscal year (FY1 in July, FY2 in September, FY3 in January, FY4 in April). Charges are calculated on the final day of the fiscal year by assessing how much content within a billing code is stored under which storage class, then multiplied by ¼ to reflect the quarterly cycle.

Example 1: A billing code has 124 GB of Archival-class content as of June 30th, so it would be charged ((124 GB * $0.60) / 4) = $18.60 on July 1st.
Example 2: A billing code has 62 GB of Sensitive-class content and 340 GB of Basic-class content as of December 31st, so it would be charged (((62 GB * $0.70) + (340 GB * $0.55)) / 4) = $57.60 on January 1st.

Although the DRS contains multiple copies of all content, units are only billed based on a single copy. Deleted content from the DRS remains recoverable for 60 days and will continue to be billed during this time.

How do I update contact information for who receives bills for our DRS owner code?

Any updates to DRS Owner and Billing codes should be submitted as a ticket through LTS. Please use the form on this wiki page: https://harvard-lts.libanswers.com/drs/faq/374206 .

How are different files for a PDS object classified?

When automatically assigned, the storage classification for a PDS object would depend on the formats utilized and roles assigned.

PDS objects with JPEG files as deliverables and TIFF files as archival copies would be classified as:
- JPEG files - Deliverable
- TIFF files - Archival
- OCR files - Deliverable
- METs file - Deliverable
PDS objects that utilize JP2000 files as a dual archival and deliverable copy would be classified as:
- JP2000 files - Repurposeable
- OCR files - Deliverable
- METs file - Deliverable

My unit has more billing codes than what appears in my quarterly bill. Why are some missing?

There is a $5 minimum billing threshold on a per-billing code, per-quarter basis. Codes assessed less than $5 in a given quarter are not included in that quarter’s billing cycle or included in that quarter’s reports. If some billing codes are missing from the quarterly statement, they likely fall under the $5 threshold.

Previous DRS Prices

The below table displays the previous prices per year for DRS storage, from 2006 - September 2022.

Fiscal Year	Cost
FY2022	$1.25 per Gigabyte per Year
FY2021	$1.25 per Gigabyte per Year
FY2020	$1.25 per Gigabyte per Year
FY2019	$1.25 per Gigabyte per Year
FY2018	$1.25 per Gigabyte per Year
FY2017	$1.50 per Gigabyte per Year
FY2016	$1.85 per Gigabyte per Year
FY2015	$1.85 per Gigabyte per Year
FY2014	$1.80 per Gigabyte per Year
FY2013	$1.50 per Gigabyte per Year
FY2012	$1.50 per Gigabyte per Year
FY2011	$1.50 per Gigabyte per Year
FY2010	$2.50 per Gigabyte per Year
FY2009	$2.50 per Gigabyte per Year
FY2008	$5.00 per Gigabyte per Year
FY2007	$5.00 per Gigabyte per Year
FY2006	$5.00 per Gigabyte per Year

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