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current software and hardware, service contracts, or lack of funding, time, or
knowledge necessary for installing an entirely new system. Instead, they seek a solu-
tion that allows the addition of long-term preservation capabilities to their existing
archives.
The existing archives may be simple file systems or more advanced archives
that include enhanced functions: “metadata” advanced query, hierarchical storage
management, routine or special error checking, disaster recovery capabilities, bit
preservation, etc. Some of these data are generated by applications that are unaware
of the OAIS specification and the AIP logical structure, and generally include just
the raw content data with minimal “metadata”. While these archives are appropriate
for short-term data retention, they cannot ensure long-term data interpretation at
some arbitrary point in the future when everything can become obsolete including
hardware, software, processes, format, people, and so forth.
PDS can be integrated with existing file systems and archives to enhance such
systems with support for OAIS-based long-term digital preservation. Figure
17.15
depicts the generic architecture for such integration. We propose the addition of
two components to the existing archive: an AIP Generator and a PDS box. The
AIP Generator wraps existing content data with an AIP, by creating a manifest file
that contains links to these data as well as relevant “metadata”, which may or may
not already exist in the archive. If some “metadata” is missing (e.g., RepInfo), the
AIP Generator will be programmed to add that part either by embedding it into
the manifest file or by saving it as a separate file or database entry linked from
the manifest file. Sometimes, programming the AIP Generator to generate those
manifest files can be quite simple, for example, if there is an existing naming scheme
that relates the various AIP parts. Note that data can be entered into the archive
using the existing data-generation applications and will, thus, not require writing
new applications.
Fig. 17.15
Integrating PDS
with an existing archive
