libvirt/src/locking/virtlockd.pod

=head1 NAME

virtlockd - libvirt lock management daemon

=head1 SYNOPSIS

B<virtlockd> [I<OPTION>]...

=head1 DESCRIPTION

The B<virtlockd> program is a server side daemon component of the libvirt
virtualization management system that is used to manage locks held against
virtual machine resources, such as their disks.

This daemon is not used directly by libvirt client applications, rather it
is called on their behalf by B<libvirtd>. By maintaining the locks in a
standalone daemon, the main libvirtd daemon can be restarted without risk
of losing locks.  The B<virtlockd> daemon has the ability to re-exec()
itself upon receiving SIGUSR1, to allow live upgrades without downtime.

The virtlockd daemon listens for requests on a local Unix domain socket.

=head1 OPTIONS

=over

=item B<-h, --help>

Display command line help usage then exit.

=item B<-d, --daemon>

Run as a daemon and write PID file.

=item B<-f, --config> I<FILE>

Use this configuration file, overriding the default value.

=item B<-t, --timeout> I<SECONDS>

Automatically shutdown after I<SECONDS> have elapsed with
no active client or lock.

=item B<-p, --pid-file> I<FILE>

Use this name for the PID file, overriding the default value.

=item B<-v, --verbose>

Enable output of verbose messages.

=item B<-V, --version>

Display version information then exit.

=back

=head1 SIGNALS

On receipt of B<SIGUSR1> virtlockd will re-exec() its binary, while
maintaining all current locks and clients. This allows for live
upgrades of the virtlockd service.

=head1 FILES

=head2 When run as B<root>.

=over

=item F<SYSCONFDIR/libvirt/virtlockd.conf>

The default configuration file used by virtlockd, unless overridden on the
command line using the B<-f>|B<--config> option.

=item F<RUNSTATEDIR/libvirt/virtlockd-sock>

The sockets libvirtd will use.

=item F<RUNSTATEDIR/virtlockd.pid>

The PID file to use, unless overridden by the B<-p>|B<--pid-file> option.

=back

=head2 When run as B<non-root>.

=over

=item F<$XDG_CONFIG_HOME/libvirt/virtlockd.conf>

The default configuration file used by libvirtd, unless overridden on the
command line using the B<-f>|B<--config> option.

=item F<$XDG_RUNTIME_DIR/libvirt/virtlockd-sock>

The socket libvirtd will use.

=item F<$XDG_RUNTIME_DIR/libvirt/virtlockd.pid>

The PID file to use, unless overridden by the B<-p>|B<--pid-file> option.

=item If $XDG_CONFIG_HOME is not set in your environment, libvirtd will use F<$HOME/.config>

=item If $XDG_RUNTIME_DIR is not set in your environment, libvirtd will use F<$HOME/.cache>

=back

=head1 EXAMPLES

To retrieve the version of virtlockd:

 # virtlockd --version
 virtlockd (libvirt) 1.1.1
 #

To start virtlockd, instructing it to daemonize and create a PID file:

 # virtlockd -d
 # ls -la RUNSTATEDIR/virtlockd.pid
 -rw-r--r-- 1 root root 6 Jul  9 02:40 RUNSTATEDIR/virtlockd.pid
 #

=head1 BUGS

Please report all bugs you discover.  This should be done via either:

=over

=item a) the mailing list

L<https://libvirt.org/contact.html>

=item or,

B<>

=item b) the bug tracker

L<https://libvirt.org/bugs.html>

=item Alternatively, you may report bugs to your software distributor / vendor.

=back

=head1 AUTHORS

Please refer to the AUTHORS file distributed with libvirt.

=head1 COPYRIGHT

Copyright (C) 2006-2013 Red Hat, Inc., and the authors listed in the
libvirt AUTHORS file.

=head1 LICENSE

virtlockd is distributed under the terms of the GNU LGPL v2.1+.
This is free software; see the source for copying conditions. There
is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE

=head1 SEE ALSO

L<libvirtd(8)>,  L<https://libvirt.org/>

=cut