6. Assigning Storage Class
- Julie Wetherill
The DRS supports dynamic disposition of all managed files to multiple storage locations according to their curatorially-designated storage classification. This file disposition is triggered by assigning a storage classification code to every content file deposited to DRS. Storage class is assigned in Batch Builder as part of batch creation and can be modified for files already in DRS storage by using DRS Web Admin. This document describes the available storage classes and how to assign them to files at deposit using Batch Builder. See the Web Admin User Guide section on Editing Administrative Metadata for instructions on assigning storage class for files already in storage.
Available storage classes
Storage class is required metadata for every content file deposited to DRS. There are six storage classes, each described in the table below:
Storage class | Curatorial/administrative/operational criteria |
Archival (AR) | Non-sensitive, non-external, non-deliverable/repurposable, non-data, non-basic, non-large file. E.g., archival master or production master files that are not also deliverable. |
Basic (BA) | Non-sensitive, non-external, non-deliverable/repurposable, non-data file designated for minimal sustaining management. (NOT IN ACTIVE USE) |
Deliverable (DE) | Non-sensitive, non-external file designated for patron retrieval. E.g., files that are deliverable or files in a deliverable object (PDS). |
Large (LG) | Non-sensitive, non-external, non-deliverable/repurposable, non-data, non-basic file greater than or equal to 5 GB in size. |
Repurposable (RE) | Non-sensitive, non-external, deliverable and also designated with an additional archivable role. E.g., deliverable jpeg2000 files that also have an archival role. |
Sensitive (SE) | File designated as containing level 4 high-risk confidential information (HRCI) under the University's security policy (Harvard University, 2019). (NOT IN ACTIVE USE) |
Assigning storage class at deposit
As of version 2.3.0 (August 2022), the Batch Builder client supports assignment of storage class to files in a deposit. The Storage Class field is located under the “Optional” tab at the directory level of the batch project. (Despite the “optional” label, this field is required.)
Screenshot of storage class field in Batch Builder:
You can manually assign storage class or let Batch Builder assign it automatically based on characteristics of the file. It is strongly recommended that you let Batch Builder set the value automatically. Note that when Batch Builder sets it automatically, the Storage Class value does not appear in the client interface (the field will appear empty) but is defined internally and will appear in the object descriptor when the batch is generated.
To assign storage class manually, select a Storage Class value on the 'Optional' metadata tab at the file directory level of your project. This way, all files with a particular role (deliverable, archival master, etc.) get assigned to the same storage locations. If you decide to assign storage class manually, be sure to pick a value that makes sense given characteristics of the file.
The table below describes Batch Builder’s criteria for auto-assigning storage class to a file.
Storage class | BatchBuilder auto-assign criteria |
Archival (AR) | File is not deliverable (access flag is not 'P' (public) or 'R' (restricted) and is smaller than 5 GB in size. All files are assumed to be AR unless file characteristics match the criteria for another storage class. |
Basic (BA) | No files are eligible for this designation (used for content from the Harvard Google Books Project). |
Deliverable (DE) | File is deliverable (access flag = 'P' (public) or 'R' (restricted)) or is a component of a PDS object (has file role = 'PAGE_COORDINATES', 'PAGE_IMAGE', or 'PAGE_TEXT'). |
Large (LG) | File size is ≥ 5 GB. |
Repurposable (RE) | File is deliverable (has access flag = 'P' (public) or 'R' (restricted)) but also has file role = 'Archival Master' or 'Production Master'. |
Sensitive (SE) | Secure storage is not yet implemented. Do not assign Secure Storage Rights metadata to objects in your batch or DRS deposit will fail. |