Overview
This module verifies the checksums derived from Islandora object datastreams and adds a PREMIS 'fixity check' entry to the object's audit log for each datastream checked. Please note that adding this entry updates the object (specifically, it changes the object's lastModifiedDate).
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With each run, the module performs checksum verification on a configurable list of object datastreams. When it has checked the datastreams of all objects (from oldest to newest), it will start from the beginning (i.e. with the oldest object in your repository) and repeat the verification cycle.
Dependencies
This module requires the following modules/libraries:
This module is only useful if you use Fedora Commons to generate checksums on datastreams. The easiest way to have Fedora Commons generate checksums is to install and enable the Islandora Checksum module.
Downloads
Release Notes and Downloads (Copy)
Installation
Install as usual, see this for further information.
Configuration
Set the cron method, number of objects to check per cron run, datastream to check, who to sent report to in Administration » Islandora » Checksum checker (admin/islandora/checksum_checker).
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The drush command you need to run is drush run-islandora-checksum-queue
. You should include drush's --root and --user options to define the path to your Drupal installation's root, and an Islandora user account that has privileges to view all datastreams, respectively. A typical Linux crontab entry (in this case, to run every hour) is:
Frequency of verification
How often you should run this command will depend on several factors, including how many objects you have in your Islandora repository and how many days or months you will tolerate between reverification of the same object's datastream checksums.
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