=head1 NAME

prdb.DB0, prdb.DBSYS1 - Contain the Protection Database and associated log

=head1 DESCRIPTION

The F<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 (B<ptserver> process)
uses the information in the database to help the File Server grant data
access to authorized users.

The F<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
operation.

Both files are in binary format and reside in the F</usr/afs/db> directory
on each of the cell's 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
AFS's 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 B<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 B<tar> command.

=head1 SEE ALSO

L<prdb_check(8)>,
L<pts(1)>,
L<ptserver(8)>

=head1 COPYRIGHT

IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.

This documentation is covered by the IBM Public License Version 1.0.  It was
converted from HTML to POD by software written by Chas Williams and Russ
Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.
