=head1 NAME

vlserver - Initializes the Volume Location Server

=head1 SYNOPSIS

=for html
<div class="synopsis">

B<vlserver> S<<< [B<-p> <I<number of threads>>] >>> [B<-nojumbo>] [B<-rxbind>]
    [B<-allow-dotted-principal>] [B<-enable_peer_stats>] [B<-enable_process_stats>] 
    [B<-help>]

=for html
</div>

=head1 DESCRIPTION

The B<vlserver> command initializes the Volume Location (VL) Server, which
runs on every database server machine. In the conventional configuration,
its binary file is located in the F</usr/afs/bin> directory on a file
server machine.

The B<vlserver> command is not normally issued at the command shell prompt
but rather placed into a file server machine's F</usr/afs/local/BosConfig>
file with the B<bos create> command. If it is ever issued at the command
shell prompt, the issuer must be logged onto a database server machine as
the local superuser C<root>.

As it initializes, the VL Server process creates the two files that
constitute the Volume Location Database (VLDB), F<vldb.DB0> and
F<vldb.DBSYS1>, in the F</usr/afs/db> directory if they do not already
exist. Use the commands in the B<vos> suite to administer the database.

The VL Server maintains the record of volume locations in the Volume
Location Database (VLDB). When the Cache Manager fills a file request from
an application program, it first contacts the VL Server to learn which
file server machine currently houses the volume that contains the file.
The Cache Manager then requests the file from the File Server process
running on that file server machine.

The VL Server records a trace of its activity in the
F</usr/afs/logs/VLLog> file. Use the B<bos getlog> command to display the
contents of the file. By default, it records on a minimal number of
messages. For instructions on increasing the amount of logging, see
L<VLLog(5)>.

By default, the VL Server runs nine lightweight processes (LWPs). To
change the number, use the B<-p> argument.

This command does not use the syntax conventions of the AFS command
suites. Provide the command name and all option names in full.

=head1 OPTIONS

=over 4

=item B<-p> <I<number of threads>>

Sets the number of server lightweight processes (LWPs or pthreads) to run.
Provide an integer between C<3> and C<16>. The default is C<9>.

=item B<-nojumbo>

Prohibits the server from sending or receiving jumbograms. A jumbogram is
a large-size packet composed of 2 to 4 normal Rx data packets that share
the same header. The VL Server uses jumbograms by default, but some
routers are not capable of properly breaking the jumbogram into smaller
packets and reassembling them.

=item B<-enable_peer_stats>

Activates the collection of Rx statistics and allocates memory for their
storage. For each connection with a specific UDP port on another machine,
a separate record is kept for each type of RPC (FetchFile, GetStatus, and
so on) sent or received. To display or otherwise access the records, use
the Rx Monitoring API.

=item B<-enable_process_stats>

Activates the collection of Rx statistics and allocates memory for their
storage. A separate record is kept for each type of RPC (FetchFile,
GetStatus, and so on) sent or received, aggregated over all connections to
other machines. To display or otherwise access the records, use the Rx
Monitoring API.

=item B<-allow-dotted-principal>

By default, the RXKAD security layer will disallow access by Kerberos
principals with a dot in the first component of their name. This is to avoid
the confusion where principals user/admin and user.admin are both mapped to the
user.admin PTS entry. Sites whose Kerberos realms don't have these collisions 
between principal names may disable this check by starting the server
with this option.

=item B<-rxbind>

Bind the Rx socket to the primary interface only.  (If not specified, the
Rx socket will listen on all interfaces.)

=item B<-help>

Prints the online help for this command. All other valid options are
ignored.

=back

=head1 EXAMPLES

The following B<bos create> command creates a vlserver process on the
machine C<fs2.abc.com> that uses six lightweight processes. Type the
command on a single line:

   % bos create -server fs2.abc.com -instance vlserver -type simple \
                -cmd "/usr/afs/bin/vlserver -p 6"

=head1 PRIVILEGE REQUIRED

The issuer must be logged in as the superuser C<root> on a file server
machine to issue the command at a command shell prompt. It is conventional
instead to create and start the process by issuing the B<bos create>
command.

=head1 SEE ALSO

L<BosConfig(5)>,
L<VLLog(5)>,
L<vldb.DB0(5)>,
L<bos_create(8)>,
L<bos_getlog(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.
