59d30adacd
After some debugging and discussion with systemd team it turns out we are misusing the ordering in libvirt-guests.service. That happened because we want to support both monolithic and modular daemon setups and on top of that we also want to support socket activation and services without socket activation. Unfortunately this is impossible to express in the unit file because of how transactions are handled in systemd when dependencies are resolved and multiple actions (jobs) are queued. For explanation from Michal Sekletar see comment #7 in the BZ this patch is fixing: https://bugzilla.redhat.com/show_bug.cgi?id=1964855#c7 In order to support all the scenarios this patch also amends the manpages so that users that are changing the default can also read how to correct the dependency ordering in libvirt-guests unit file. Ideally we would also keep the existing configuration during upgrade, but due to our huge support matrix this seems hardly feasible as it could introduce even more problems. Signed-off-by: Martin Kletzander <mkletzan@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
6.6 KiB
virtqemud
libvirt QEMU management daemon
- Manual section
8
- Manual group
Virtualization Support
SYNOPSIS
virtqemud [OPTION]...
DESCRIPTION
The virtqemud program is a server side daemon component of the libvirt virtualization management system.
It is one of a collection of modular daemons that replace functionality previously provided by the monolithic libvirtd daemon.
This daemon runs on virtualization hosts to provide management for QEMU virtual machines.
The virtqemud daemon only listens for requests on a local Unix domain socket. Remote off-host access and backwards compatibility with legacy clients expecting libvirtd is provided by the virtproxy daemon.
Restarting virtqemud does not interrupt running guests. Guests continue to operate and changes in their state will generally be picked up automatically during startup. None the less it is recommended to avoid restarting with running guests whenever practical.
SYSTEM SOCKET ACTIVATION
The virtqemud daemon is capable of starting in two modes.
In the traditional mode, it will create and listen on UNIX sockets itself.
In socket activation mode, it will rely on systemd to create and listen on the UNIX sockets and pass them as pre-opened file descriptors. In this mode most of the socket related config options in /etc/libvirt/virtqemud.conf will no longer have any effect.
Socket activation mode is generally the default when running on a host OS that uses systemd. To revert to the traditional mode, all the socket unit files must be masked:
$ systemctl mask virtqemud.socket virtqemud-ro.socket \
virtqemud-admin.socketIf using libvirt-guests service then the ordering for that service needs to be adapted so that it is ordered after the service unit instead of the socket unit. Since dependencies and ordering cannot be changed with drop-in overrides, the whole libvirt-guests unit file needs to be changed. In order to preserve such change copy the installed /usr/lib/systemd/system/libvirt-guests.service to /etc/systemd/system/libvirt-guests.service and make the change there, specifically make sure the After= ordering mentions virtqemud.service and not virtqemud.socket:
[Unit]
After=virtqemud.serviceOPTIONS
-h, --help
Display command line help usage then exit.
-d, --daemon
Run as a daemon & write PID file.
-f, --config *FILE*
Use this configuration file, overriding the default value.
-p, --pid-file *FILE*
Use this name for the PID file, overriding the default value.
-t, --timeout *SECONDS*
Exit after timeout period (in seconds), provided there are neither any client connections nor any running domains.
-v, --verbose
Enable output of verbose messages.
--version
Display version information then exit.
SIGNALS
On receipt of SIGHUP virtqemud will reload its configuration.
FILES
When run as root
@SYSCONFDIR@/libvirt/virtqemud.conf
The default configuration file used by virtqemud, unless overridden on the command line using the -f | --config option.
In addition to the default configuration file, virtqemud reads configuration for the QEMU driver from:
@SYSCONFDIR@/libvirt/qemu.conf
This file contains various knobs and default values for virtual machines created within QEMU driver, and offers a way to override the built in defaults, for instance (but not limited to): paths to various supplementary binaries, TLS certificates location, graphical consoles configuration and others. Location of this file can't be overridden by any command line switch.
@RUNSTATEDIR@/libvirt/virtqemud-sock@RUNSTATEDIR@/libvirt/virtqemud-sock-ro@RUNSTATEDIR@/libvirt/virtqemud-admin-sock
The sockets virtqemud will use.
The TLS Server private key virtqemud will use.
@RUNSTATEDIR@/virtqemud.pid
The PID file to use, unless overridden by the -p | --pid-file option.
When run as non-root
$XDG_CONFIG_HOME/libvirt/virtqemud.conf
The default configuration file used by virtqemud, unless overridden on the command line using the -f|--config option.
In addition to the default configuration file, virtqemud reads configuration for the qemu driver from:
$XDG_CONFIG_HOME/libvirt/qemu.conf
If the file exists, it can contain various knobs and default values for virtual machines created within QEMU driver, and offers a way to override the built in defaults, for instance (but not limited to): paths to various supplementary binaries, TLS certificates location, graphical consoles configuration and others. Location of this file can't be overridden by any command line switch.
$XDG_RUNTIME_DIR/libvirt/virtqemud-sock$XDG_RUNTIME_DIR/libvirt/virtqemud-admin-sock
The sockets virtqemud will use.
$XDG_RUNTIME_DIR/libvirt/virtqemud.pid
The PID file to use, unless overridden by the -p|--pid-file option.
If $XDG_CONFIG_HOME is not set in your environment, virtqemud will use $HOME/.config
If $XDG_RUNTIME_DIR is not set in your environment, virtqemud will use $HOME/.cache
EXAMPLES
To retrieve the version of virtqemud:
# virtqemud --version
virtqemud (libvirt) @VERSION@To start virtqemud, instructing it to daemonize and create a PID file:
# virtqemud -d
# ls -la @RUNSTATEDIR@/virtqemud.pid
-rw-r--r-- 1 root root 6 Jul 9 02:40 @RUNSTATEDIR@/virtqemud.pidBUGS
Please report all bugs you discover. This should be done via either:
the mailing list
the bug tracker
Alternatively, you may report bugs to your software distributor / vendor.
AUTHORS
Please refer to the AUTHORS file distributed with libvirt.
COPYRIGHT
Copyright (C) 2006-2020 Red Hat, Inc., and the authors listed in the libvirt AUTHORS file.
LICENSE
virtqemud 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
SEE ALSO
virsh(1), libvirtd(8), https://www.libvirt.org/daemons.html, https://www.libvirt.org/drvqemu.html