Improvements/Disk Image Preservation
Synopsis
This project is being sponsored by UCLA Library and NYPL Special Collections but more collaborators are welcome! Please get in touch on the community user forum.
Different tools are needed for extraction of different disk images depending on what file system the disk image was created from. Archivematica's standard tool for disk image extraction is tsk recover, which is limited to 18 file systems. A challenge to invoking the right tool for the job is Archivematica's use of file format, rather than other characteristics (in this case, the file system). For example, if a disk image is identified as an ISO image, Archivematica will currently invoke tsk recover regardless of the file system of the image, where as tsk recover will only be able to extract the contents of the 18 file systems listed in the link above.
In this project we are particularly focused on hfs disk images, which are not currently supported by tsk recover, but the development will be generic enough to be useful to different types of disk images as well.
User story
As an archivist, I would like to process disk images of an unknown file-system through Archivematica, and have Archivematica and/or its associated tools recognize and record the file system and choose appropriate tools for disk image extraction and characterization. Further, I would want to be able to pull statistics about the size and file-type of disk images from the system.
Development tasks
We have identified the following development tasks which would need to be addressed in the order described:
Automation tool script
Develop an automation tool script which would identify the file system and store this metadata in such a way that it can be passed to Archivematica.
Disk image transfer type
Currently, the disk image transfer type in Archivematica offers additional metadata entry but no additional functionality. This development would enable Archivematica to understand that disk image transfers have metadata associated with the file system type, and then act on that information.
File extraction
Implement tools such as HFS Utilities that will allow files from hfs disk images to be extracted.
Characterize
Write meaningful characterization (possibly as dfxml in the METS file) about the size and file type of the disk images so that statistics can be gathered from the AIPs.
Tools/resources
- HFS Utilities
- hfs2dfxml - Utility to parse hfsutils output and produce DFXML for HFS-formatted disk images