Archivematica 1.11.2 is our latest release.

AIP structure

This page describes the standard structure of an AIP produced by Archivematica.

On this page:

Name

The AIP name is composed of the following:

  1. The name assigned to the transfer. This may come from human input or it may be the name of the transfer directory, depending on the transfer type and the transfer method.
  2. A UUID assigned to the AIP during ingest.

For example, looking at the AIP name my-aip-d31cc44f-ce01-4e67-affe-513868d9cf3d, my-aip is the name assigned by the user and d31cc44f-ce01-4e67-affe-513868d9cf3d is the UUID generated during ingest.

AIP contents

Archivematica AIPs are structurally consistent regardless of variables in original content, processing, and storage. They are is packaged into a bag in accordance with the IETF Trust BagIt File Packaging Format. This tree structure depicts a typical Archivematica AIP:

[1] my-aip-d31cc44f-ce01-4e67-affe-513868d9cf3d
[2] ├── bag-info.txt
[3] ├── bagit.txt
[4] ├── manifest-sha512.txt
[5] ├── tagmanifest-md5.txt
[6] └── data
[7]     ├── logs
[8]     ├── objects
[9]     ├── thumbnails
[10]    ├── METS.d31cc44f-ce01-4e67-affe-513868d9cf3d.xml
[11]    └── README.html

For more information about each of these components, see the appropriate section below.

BagIt files

Archivematica uses a very simple implementation of BagIt. All AIPs contain the following BagIt files:

  • bag-info.txt: a tag file that contains metadata about the bag, including:

    • Payload-Oxum: the octet stream sum of the bag payload.
    • Bagging-Date: a yyyy-mm-dd formatted date on which the bag was created (e.g. 2018-11-01).
    • Bag-Size: a human-readable file size (e.g. 42kB).
    • External-Identifier: the UUID of the AIP.
  • bagit.txt: the bag declaration, stating the version and encoding.

  • manifest-sha256.txt: a list of each payload file name with corresponding SHA256 checksums.

  • tagmanifest-md5.txt: a tag file that lists other tag files with corresponding MD5 checksums.

This example shows the contents of the top-level directory of the AIP.

my-aip-d31cc44f-ce01-4e67-affe-513868d9cf3d
├── bag-info.txt
├── bagit.txt
├── data
├── manifest-sha256.txt
└── tagmanifest-sha256.txt

Data directory

The data directory consists of the METS file for the AIP, a README file, and three folders: logs, objects and thumbnails.

This example shows the contents of the AIP’s data directory.

my-aip-d31cc44f-ce01-4e67-affe-513868d9cf3d
└── data
    ├── logs
    ├── METS.d31cc44f-ce01-4e67-affe-513868d9cf3d.xml
    ├── objects
    ├── README.html
    └── thumbnails

AIP METS file

The AIP METS file, /data/METS.uuid.xml, lists all of the digital objects in the AIP (original files, preservation masters, license files, OCR text files, submission documentation, etc.), describes their relationships to each other, and links digital objects to their descriptive, technical, provenance, and rights metadata.

The AIP METS file name is composed from the prefix METS., the UUID of the AIP, and the extension .xml. Note that the presence of the UUID differentiates the AIP METS file from the transfer METS file, described in the Objects section below.

For more information about Archivematica’s METS implementation, see METS in Archivematica.

README file

The AIP README file, /data/README.html, is a human-readable file that describes the basic structure of an Archivematica AIP. It introduces Archivematica, OAIS, METS and PREMIS, and other concepts that future users may find helpful when they encounter an AIP.

Logs

The logs directory, /data/logs, contains log outputs for some of the tools and tasks that run inside of Archivematica.

This is an example of the contents of an AIP’s logs directory:

my-aip-d31cc44f-ce01-4e67-affe-513868d9cf3d
└── data
    └── logs
        ├── arrange.log
        ├── fileFormatIdentification.log
        ├── filenameCleanup.log
        └── transfers
            ├── first-transfer-abbff451-f077-4f66-a6e0-d83f6ebbeebf
            │   └── logs
            │       ├── fileFormatIdentification.log
            │       └── filenameCleanup.log
            └── second-transfer-52fd11fa-fca8-4bc7-9214-e6510863759a
                └── logs
                    ├── fileFormatIdentification.log
                    └── filenameCleanup.log

The top-level logs (arrange.log, fileFormatIdentification.log, etc.) are outputs for tasks that took place either in the Appraisal tab or on the Ingest tab. For example, data/logs/fileFormatIdentification.log is the log that was created during the Identify file format job that takes place during the Normalize microservice on the Ingest tab.

The logs directory has a transfers subdirectory, /data/logs/transfers, which contains logs for tools that ran on the Transfer tab. Since it is possible to combine multiple transfers into one SIP (which becomes one AIP), the transfers subdirectory may contain multiple directories. Continuing to use the example above, two transfers (first-transfer and second-transfer) were combined to create one AIP (my-aip). Therefore, there are two more fileFormatIdentification.log files:

  • data/logs/transfers/first-transfer-abbff451-f077-4f66-a6e0-d83f6ebbeebf/logs/fileFormatIdentification.log is the log that was created during Microservice: Identify file format on the Transfer tab when first-transfer was processed.
  • data/logs/transfers/second-transfer-52fd11fa-fca8-4bc7-9214-e6510863759a/logs/fileFormatIdentification.log is the log that was created during Microservice: Identify file format on the Transfer tab when second-transfer was processed.

The example above does not show all possible logs. Depending on how you have set your Processing configuration, you may see a greater or lesser number of logs or logs of different types in your AIP.

Objects

The objects directory, /data/objects, contains original objects, preservation masters, and two folders: /metadata and /submissionDocumentation. If the SIP contained any lower-level directories, either from the original transfer or because it was arranged on the Appraisal tab, the lower-level directories will be present as well.

my-aip-d31cc44f-ce01-4e67-affe-513868d9cf3d
└── data
    └── objects
        ├── 799px-Euroleague-LE_Roma_vs_Toulouse_IC-27-3e2bcabd-f33f-485b-a566-ff71c141b930.tif
        ├── 799px-Euroleague-LE_Roma_vs_Toulouse_IC-27.bmp
        ├── BBhelmet.ai
        ├── G31DS-60559b5e-38a5-44f5-8c63-bb41bda5d2e8.tif
        ├── G31DS.TIF
        ├── metadata
        │   └── transfers
        │       ├── first-transfer-abbff451-f077-4f66-a6e0-d83f6ebbeebf
        │       │   ├── directory_tree.txt
        │       │   └── metadata.csv
        │       └── second-transfer-52fd11fa-fca8-4bc7-9214-e6510863759a
        │           └── directory_tree.txt
        └── submissionDocumentation
            ├── transfer-first-transfer-abbff451-f077-4f66-a6e0-d83f6ebbeebf
            │   └── METS.xml
            └── second-transfer-52fd11fa-fca8-4bc7-9214-e6510863759a
                └── METS.xml

The filenames of original objects will be unchanged. Preservation master copies have a UUID appended to the filename. In the example above, 799px-Euroleague-LE_Roma_vs_Toulouse_IC-27.bmp is the original object and 799px-Euroleague-LE_Roma_vs_Toulouse_IC-27-3e2bcabd-f33f-485b-a566-ff71c141b930.tif is the preservation master. The creation of preservation master copies is guided by the rules on the Preservation planning tab.

The /metadata directory contains metadata associated with the AIP. The metadata directory has a transfers subdirectory, /data/metadata/transfers, which separates the metadata files into folders specific to the transfer where they originated. Since it is possible to combine multiple transfers into one SIP (which becomes one AIP), the transfers subdirectory may contain multiple folders.

The /submissionDocumentation directory contains submission documentation for the AIP. Similar to the metadata directory, there is a transfers subdirectory, /data/submissionDocumentation/transfers, which separates the submission documentation files into folders specific to the transfer where they originated. Since it is possible to combine multiple transfers into one SIP (which becomes one AIP), the transfers subdirectory may contain multiple folders. Note that the transfer folders contain a METS.XML file - this is the transfer METS, which was generated for each transfer on the Transfer tab. When the transfer (or multiple transfers combined) become a SIP, the transfer METS files are combined into a new METS file which becomes the AIP METS file.

Thumbnails

The objects directory, /data/thumbnails, will contain thumbnail images if you chose to generate them during the Normalize for thumbnails job.

my-aip-d31cc44f-ce01-4e67-affe-513868d9cf3d
└── data
    └── thumbnails
        ├── 0e9fd6db-ac57-453c-ba0f-c9cff9d0ac56.jpg
        ├── 7d1c5e44-f1e1-4cf7-8b79-ca2284a6ce79.jpg
        └── dd1a6fb8-7e49-47ca-921b-87b234c939b9.jpg

The creation of thumbnails is optional and configurable in the processing configuration.

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