The prdb.DB0 file contains the Protection Database, which maps AFS
user, machine, and group names to their respective IDs (AFS UIDs and GIDs)
and tracks group memberships. The Protection Server (ptserver process)
uses the information in the database to help the File Server grant data
access to authorized users.
The prdb.DBSYS1 file is a log file in which the Protection Server logs
each database operation before performing it. When an operation is
interrupted, the Protection Server replays the log to complete the
Both files are in binary format and reside in the /var/openafs/db directory
on each of the cells database server machines. When the Protection Server
starts or restarts on a given machine, it establishes a connection with
its peers and verifies that its copy of the database matches the copy on
the other database server machines. If not, the Protection Servers call on
AFSs distributed database technology, Ubik, to distribute to all of the
machines the copy of the database with the highest version number.
Always use the commands in the pts suite to administer the Protection
Database. It is advisable to create an archive copy of the database on a
regular basis, using a tool such as the UNIX tar command.