mirror of https://gitlab.com/libvirt/libvirt.git synced 2024-11-09 23:10:08 +00:00

Benjamin Taubmann a39dd25715 Extend libvirt-guests to shutdown only persistent VMs

At the moment, there is no configuration option for the libvirt-guests
service that allows users to define that only persistent virtual machines
should be shutdown on host shutdown.

Currently, the service config allows to choose between two ON_SHUTDOWN
actions that are executed on running virtual machines when the host goes
down: shutdown, suspend.
The ON_SHUTDOWN action should be orthogonal to the type of the virtual
machine. However, the existing implementation, does not suspend
transient virtual machines.
This is the matrix of actions that is executed on virtual machines based
on the configured ON_SHUTDOWN action and the type of a virtual machine.

         | persistent | transient
shutdown | shutdown   | shutdown (what we want to change)
suspend  | suspend    | nothing

Add config option PERSISTENT_ONLY to libvirt-guests config that allows
users to define if the ON_SHUTDOWN action should be applied only on
persistent virtual machines. PERSISTENT_ONLY can be set to true, false,
default. The default option will implement the already existing logic.

Case 1: PERSISTENT_ONLY=default
         | persistent | transient
shutdown | shutdown   | shutdown
suspend  | suspend    | nothing

Case 2: PERSISTENT_ONLY=true
         | persistent | transient
shutdown | shutdown   | nothing
suspend  | suspend    | nothing

Case 3: PERSISTENT_ONLY=false
         | persistent | transient
shutdown | shutdown   | shutdown
suspend  | suspend    | suspend

Signed-off-by: Benjamin Taubmann <benjamin.taubmann@nutanix.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>

2024-04-04 09:10:00 +02:00

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libvirt-guests

suspend/resume running libvirt guests

Manual section: 8
Manual group: Virtualization Support

SYNOPSIS

libvirt-guests COMMAND

DESCRIPTION

libvirt-guests is a service that can be used to coordinate guest and host lifecycle actions. By default, libvirt-guests will suspend running guests when the host shuts down, and restore them to their pre-shutdown state when the host reboots.

libvirt-guests is typically under control of systemd. When libvirt-guests.service is enabled, systemd will call libvirt-guests with the start COMMAND when the host boots. Conversely, systemd will call libvirt-guests with the stop COMMAND when the host shuts down.

libvirt-guests can be used directly. In addition to the start and stop COMMANDs, it also supports status, restart, condrestart, try-restart, reload, force-reload, gueststatus, and shutdown COMMANDs.

FILES

libvirt-guests defines several variables to control service behavior. The default value of these variables can be overridden in:

@INITCONFDIR@/libvirt-guests

The following variables are supported:

URIS=default

URIs to check for running guests. Example: URIS='default xen:///system xen+tcp://host/system lxc:///system'
ON_BOOT=start

Action taken on host boot
- start
  
  All guests which were running on shutdown are started on boot regardless of their autostart settings
- ignore
  
  libvirt-guests won't start any guest on boot, however, guests marked as autostart will still be automatically started by libvirtd
START_DELAY=0

Number of seconds to wait between each guest start. Set to 0 to allow parallel startup.
ON_SHUTDOWN=suspend

Action taken on host shutdown
- suspend
  
  All running guests are suspended using virsh managedsave
- shutdown
  
  All running guests are asked to shutdown. Please be careful with this settings since there is no way to distinguish between a guest which is stuck or ignores shutdown requests and a guest which just needs a long time to shutdown. When setting ON_SHUTDOWN=shutdown, you must also set SHUTDOWN_TIMEOUT to a value suitable for your guests.
PARALLEL_SHUTDOWN=0

Number of guests will be shutdown concurrently, taking effect when "ON_SHUTDOWN" is set to "shutdown". If Set to 0, guests will be shutdown one after another. Number of guests on shutdown at any time will not exceed number set in this variable.
SHUTDOWN_TIMEOUT=300

Number of seconds we're willing to wait for a guest to shut down. If parallel shutdown is enabled, this timeout applies as a timeout for shutting down all guests on a single URI defined in the variable URIS. If this is 0, then there is no time out (use with caution, as guests might not respond to a shutdown request). The default value is 300 seconds (5 minutes).
BYPASS_CACHE=0

If non-zero, try to bypass the file system cache when saving and restoring guests, even though this may give slower operation for some file systems.
SYNC_TIME=0

If non-zero, try to sync guest time on domain resume. Be aware, that this requires guest agent with support for time synchronization running in the guest. By default, this functionality is turned off.
PERSISTENT_ONLY=default

Defines what type of guest virtual machine ON_SHUTDOWN action is applied to
- default
  
  This implements the already existing default behavior. If ON_SHUTDOWN action is shutdown, transient and persistent guest virtual machines are asked to shutdown. If ON_SHUTDOWN action is suspend, only persistent guest virtual machines are asked to suspend.
- true
  
  ON_SHUTDOWN action is executed only on persistent guest virtual machines. Transient guest virtual machines are not affected.
- false
  
  ON_SHUTDOWN action is executed on persistent and transient guest virtual machines.

BUGS

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

the mailing list

https://libvirt.org/contact.html
the bug tracker

https://libvirt.org/bugs.html

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

AUTHORS

Please refer to the AUTHORS file distributed with libvirt.

LICENSE

libvirt-guests 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

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