Methodology

Don’t put all your eggs in one basket.

Good advice for eggs is also good advice for digital collections. Protecting your archives from disasters (natural or man-made), human error, and degradation is the driving force behind our Distributed Digital Preservation methodology. Here’s how it works.

  • The MetaArchive Cooperative uses LOCKSS (Lots of Copies Keep Stuff Safe) software, developed at Stanford University. LOCKSS allows us to embed the technical infrastructure and the knowledge base within our own individual libraries instead of with an outside vendor.
  • Files are contributed to a secure, closed-access network of servers set up between the MetaArchive Cooperative’s members. These files are for preservation only, not for access by the other sites.
  • Each institution in the Cooperative runs a server that is linked securely to the network. And all servers are stored in different geographic locations and maintained by different systems administrators.
  • After an institution readies content for ingest, the content source is visited by six of the network’s servers and a server maintained by the Library of Congress, each of which replicates and preserves a copy. Servers are selected and assigned to content on the basis of their widespread geographical distribution.
  • All seven servers then revisit the content source on a regular basis to pick up any content that has been changed or added.
  • When new or changed content is detected, it is stored alongside the original so that any version can be recovered. (This is called versioning, and it’s something many other preservation approaches cannot do at all.)
  • The seven servers also check in with each other to make sure that all seven copies are identical. If a mismatch is detected, the servers come to quorum regarding which copies are correct and which do not match, and then the network repairs the “bad” files.
  • Again, the repair is stored alongside the original so that no file version is ever lost/replaced within the system.
  • MetaArchive staff members, experts in preservation, work closely with each member institution as it prepares its collections for ingest/preservation and as it sets up its server within the secure network.