The repository shall have procedures for all actions taken on AIPs.

This is necessary in order to ensure that any actions performed against an AIP do not alter the AIP information in a manner unacceptable to its Designated Communities.

Written documentation describing all actions that can be performed against an AIP.

This documentation is normally created during design of the repository. It should detail the normal handling of AIPs, all actions that can be performed against the AIPs, including success and failure conditions and details of how these processes can be monitored.

The Preservation and Storage section covers the regular preservation lifestyle and storage considerations for digital files being preserved by APTrust.

APTrust stores one copy on the East Coast (Virginia) and one copy on the West Coast (Oregon). East Coast copies are in hot storage, and West Coast copies are in cold storage.

APTrust performs fixity checking on hot copies of individual files every 180 days. Fixity checks do not alter the AIP or any of its component files. Failed fixity checks generate alerts to both APTrust staff and the depositing institution.

When a fixity check fails, indicating a missing or corrupt file, APTrust retrieves the cold copy and verifies fixity before replacing the corrupted hot copy. This process currently requires intervention from APTrust staff via scripts we manually run to repair missing and corrupt files. We ran them in 2017 to fix a number of files that were incorrectly copied to long-term storage upon ingest, so we know the scripts work.

APTrust also provides a “restoration” feature. APTrust rebuilds bags for restoration, therefore the bag the depositor gets back will not exactly match the bag that was deposited, though APTrust does guarantee that it contains all of the latest versions of all of the payload files.

The restoration process does not alter or delete the AIP files in the preservation storage area.

APTrust also provides a deletion feature described in the Deletion section. The system will delete the object or file from preservation storage only after the depositor’s administrative user approves the action. Upon deletion, the system creates a PREMIS event describing when the object was deleted, and at whose request. The system also keeps tombstone records of all deleted objects and files. The tombstone records are identical to the records of existing items, except that the item’s State attribute is changed from “Active” to “Deleted”.

For more information see APTrust Preservation Policy.