[PATCH pve-docs 6/6] qm: add reboot behavior information

[Jakob Klocker <j.klocker@proxmox.com>]

Add information about the newly created `Reboot behavior` option in PVE.

Signed-off-by: Jakob Klocker <j.klocker@proxmox.com>
---
 qm.adoc | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/qm.adoc b/qm.adoc
index 96ba68b..e900cb8 100644
--- a/qm.adoc
+++ b/qm.adoc
@@ -1540,6 +1540,43 @@ cluster-wide.
 If you require a delay between the host boot and the booting of the first VM,
 see the section on xref:first_guest_boot_delay[Proxmox VE Node Management].
 
+[[qm_reboot_behavior]]
+Reboot Behavior
+~~~~~~~~~~~~~~~
+
+When a guest reboots itself from inside the operating system, {pve} does not
+need to restart the virtual machine to service the request. By default the
+machine is reset in place: the QEMU process keeps running and only the guest
+operating system boots again.
+
+This is fast and transparent to the guest, but it means the VM keeps running
+with everything it was started with - its configuration, its machine version
+and the host resources assigned to it. Configuration changes that are marked as
+*pending* in the *Options* and hardware panels therefore stay pending, and a
+newer `pve-qemu-kvm` package installed in the meantime is not picked up. A
+reboot triggered through the web interface, `qm` or the API is not affected by
+this, as it always stops and starts the virtual machine, unless rebooting is
+disabled entirely.
+
+The `reboot` option has two properties:
+
+`enabled` (default: `1`)::
+Whether the virtual machine may reboot at all. If disabled, the VM is shut down
+instead of rebooted and stays off, no matter whether the reboot was initiated by
+the guest or through {pve}. Note that guests managed by the
+xref:chapter_ha_manager[HA stack] with the requested state `started` are started
+again by the HA manager.
+
+`powercycle` (default: `0`)::
+Stop and start the virtual machine on a reset instead of resetting it in place.
+Because this is a full start, pending configuration changes take effect and the
+VM is launched with the currently installed QEMU version. This applies to resets
+initiated inside the guest as well as to those triggered through the web
+interface, `qm` or the API. This has no effect when reboot is disabled.
+
+----
+# qm set <vmid> --reboot 1,powercycle=1
+----
 
 [[qm_qemu_agent]]
 QEMU Guest Agent
-- 
2.47.3