If you simply want to validate an existing bag, follow these steps:
Choose Jobs > Validate a Bag from the menu.
Choose the BagIt profile against which you want to validate. If you want to validate against the BagIt specification instead of a specific profile, choose the "Empty Profile."
Choose whether you want to validate a tarred or untarred bag. As of version 2.0.4 (March, 2020), DART supports only tarred and unserialized bags (i.e. a bag that is a folder). We plan to support additional formats in the future.
Click Browse to choose the folder or tar file you want to validate.
The progress bar will show the progress of the job, and DART will display specific error messages below the progress bar when the job is complete.
Note that a bag that is valid according to one profile may be invalid according to others. If a bag is valid according to the Empty Profile, it conforms to the general IETF BagIt specification.
A Note on Mac OS Dot-Underscore Files
DART may report a number of errors for tarred bags created on Mac OS, stating that .DS_Store files or files beginning with "._" were found in the payload but not in the manifests.
Typically, there will be one dot-underscore file for each payload file, like so:
- data/article.pdf -> data/._article.pdf
- data/image.jpg -> data/._image.jpg
These files contain metadata used by the Mac OS filesystem. When you tar a bag with the typical command,
tar -cf mybag.tar mybag, Mac includes the dot-underscore files by default, but your bagging software may not include those hidden files in the manifests, so the DART validator considers the bags invalid, with messages like "File data/._image.jpg found in data directory is not present in manifest-sha256.txt."
When tarring your own bags outside of DART, you get around this problem with the command
COPYFILE_DISABLE=1 tar -cf mybag.tar mybag. That tells Mac's tar program to exclude dot-underscore files from the tarball.