Essential Readiness

BagIt provides an easy way to create checksums and keep this information closely associated with the content for which it was created. An institution with little to no access to technical staff or expertise can follow the README instructions for a BagIt tool like Bagger and begin creating “bags” of collection content that will include a file called manifest-md5.txt or manifest-sha256.txt. This manifest file will include a per-file listing of all collection files targeted for checksum creation and list out the individual checksums inline with that file. The filename indicates the algorithm used. Bagged content can be routinely validated with the BagIt tools. For example, Bagger has a feature that checks whether a file may be missing from the manifest of files. If all files are present another feature can be used to validate the current set of files—in other words calculate a new set of checksums and compare them back against those listed in the manifest. The command-line versions of the BagIt utilities have options and arguments that can be invoked to perform these same operations.