Merci @Zargos pour ce retour.
Oui j’ai voulu faire vite avec les captures seules.
En faisant un export des logs (avec journalctl -b > export.txt) à partir du redémarrage, j’arrive à trouver des enregistrements de faits tels que (liste non exhaustive et possibles doublons venant des logs) :
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: Clearing orphaned inode 2339 (uid=1000, gid=1000, mode=0100644, size=775168)
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: Clearing orphaned inode 4533 (uid=1000, gid=1000, mode=0100644, size=23612)
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: Clearing orphaned inode 1480 (uid=1000, gid=1000, mode=0100644, size=68668)
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: Clearing orphaned inode 4511 (uid=1000, gid=1000, mode=0100644, size=40348)
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: Clearing orphaned inode 1905 (uid=1000, gid=1000, mode=0100644, size=59360)
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: Clearing orphaned inode 1483 (uid=1000, gid=1000, mode=0100644, size=16100)
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: Clearing orphaned inode 1776 (uid=1000, gid=1000, mode=0100644, size=22128)
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: Clearing orphaned inode 1470 (uid=1000, gid=1000, mode=0100644, size=38300)
déc. 17 00:04:29 debian systemd-fsck[489]: HOME: clean, 5049/184736 files, 92880/734208 blocks
...
déc. 17 00:04:30 debian systemd-fsck[571]: fsck.fat 4.2 (2021-01-31)
déc. 17 00:04:30 debian systemd-fsck[571]: There are differences between boot sector and its backup.
déc. 17 00:04:30 debian systemd-fsck[571]: This is mostly harmless. Differences: (offset:original/backup)
déc. 17 00:04:30 debian systemd-fsck[571]: 65:01/00
déc. 17 00:04:30 debian systemd-fsck[571]: Not automatically fixing this.
déc. 17 00:04:30 debian systemd-fsck[571]: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
déc. 17 00:04:30 debian systemd-fsck[571]: Automatically removing dirty bit.
déc. 17 00:04:30 debian systemd-fsck[571]: *** Filesystem was changed ***
déc. 17 00:04:30 debian systemd-fsck[571]: Writing changes.
déc. 17 00:04:30 debian systemd-fsck[571]: /dev/sda1: 193 files, 34599/98304 clusters
...
déc. 17 00:06:58 debian sddm-helper[1381]: Failed to write utmpx: No such file or directory
...
déc. 17 00:07:10 debian plasmashell[1650]: libEGL warning: pci id for fd 7: 80ee:beef, driver (null)
déc. 17 00:07:10 debian plasmashell[1650]: pci id for fd 15: 80ee:beef, driver (null)
déc. 17 00:07:10 debian plasmashell[1650]: kmsro: driver missing
déc. 17 00:07:10 debian plasmashell[1650]: libEGL warning: egl: failed to create dri2 screen
déc. 17 00:07:10 debian plasmashell[1650]: pci id for fd 15: 80ee:beef, driver (null)
déc. 17 00:07:10 debian plasmashell[1650]: kmsro: driver missing
déc. 17 00:07:10 debian plasmashell[1650]: libEGL warning: egl: failed to create dri2 screen
...
déc. 17 00:07:11 debian kded6[1596]: QDBusObjectPath: invalid path "/modules/oom-notifier"
déc. 17 00:07:11 debian kded6[1596]: kf.dbusaddons: The kded module name "oom-notifier" is invalid!
...déc. 17 00:07:12 debian kded6[1596]: QDBusObjectPath: invalid path "/modules/plasma-session-shortcuts"
déc. 17 00:07:12 debian kded6[1596]: kf.dbusaddons: The kded module name "plasma-session-shortcuts" is invalid!
déc. 17 00:07:12 debian kded6[1596]: QDBusObjectPath: invalid path "/modules/wpad-detector"
déc. 17 00:07:12 debian kded6[1596]: kf.dbusaddons: The kded module name "wpad-detector" is invalid!
déc. 17 00:07:12 debian kded6[1596]: org.kde.libkbolt: Failed to connect to Bolt manager DBus interface:
déc. 17 00:07:12 debian kded6[1596]: org.kde.bolt.kded: Couldn't connect to Bolt DBus daemon
déc. 17 00:07:12 debian kded6[1596]: org.kde.kameleon: found no RGB LED devices
déc. 17 00:07:12 debian kded6[1596]: org.kde.colorcorrectlocationupdater: Geolocator stopped
déc. 17 00:07:13 debian plasmashell[1650]: org.kde.plasma.libtaskmanager: The PlasmaWindowManagement protocol hasn't activated in time. The client possibly got denied by kwin? Check kwin output.
...
déc. 17 00:07:22 debian plasmashell[1650]: file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/main.qml:310:13: QML Image: Cannot open: file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/start-here-kde-symbolic
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "preferred://browser" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "org.kde.kontact.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "systemsettings.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "org.kde.dolphin.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "ktp-contactlist.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "org.kde.discover.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "preferred://browser" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "org.kde.kontact.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "systemsettings.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "org.kde.dolphin.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "ktp-contactlist.desktop" 0x5633d05c1aa0
déc. 17 00:07:22 debian plasmashell[1650]: org.kde.plasma.kicker: Entry is not valid "org.kde.discover.desktop" 0x5633d05c1aa0
...
déc. 17 00:07:30 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:07:30 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:07:30 debian plasmashell[1650]: kpipewire_logging: Failed to create PipeWire context
déc. 17 00:07:30 debian plasmashell[1650]: received error while creating the stream "Impossible de créer un contexte pour PipeWire" Media monitor will not work.
déc. 17 00:07:34 debian kwin_wayland_wrapper[1472]: kwin_wayland_drm: The main thread was hanging temporarily!
déc. 17 00:07:36 debian kded6[1596]: Registering ":1.64/org/ayatana/NotificationItem/ibus_ui_gtk3" to system tray
déc. 17 00:07:37 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:07:37 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:07:37 debian plasmashell[1650]: kpipewire_logging: Failed to create PipeWire context
déc. 17 00:07:37 debian plasmashell[1650]: received error while creating the stream "Impossible de créer un contexte pour PipeWire" Media monitor will not work.
déc. 17 00:07:42 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:07:42 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:07:42 debian plasmashell[1650]: kpipewire_logging: Failed to create PipeWire context
déc. 17 00:07:42 debian plasmashell[1650]: received error while creating the stream "Impossible de créer un contexte pour PipeWire" Media monitor will not work.
...
déc. 17 00:07:48 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:07:48 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:07:48 debian plasmashell[1650]: kpipewire_logging: Failed to create PipeWire context
déc. 17 00:07:48 debian plasmashell[1650]: received error while creating the stream "Impossible de créer un contexte pour PipeWire" Media monitor will not work.
...
déc. 17 00:08:16 debian systemsettings[2212]: libEGL warning: pci id for fd 16: 80ee:beef, driver (null)
déc. 17 00:08:16 debian systemsettings[2212]: pci id for fd 17: 80ee:beef, driver (null)
déc. 17 00:08:16 debian systemsettings[2212]: kmsro: driver missing
déc. 17 00:08:16 debian systemsettings[2212]: libEGL warning: egl: failed to create dri2 screen
déc. 17 00:08:17 debian systemsettings[2212]: pci id for fd 17: 80ee:beef, driver (null)
déc. 17 00:08:17 debian systemsettings[2212]: kmsro: driver missing
déc. 17 00:08:17 debian systemsettings[2212]: libEGL warning: egl: failed to create dri2 screen
déc. 17 00:08:19 debian systemsettings[2212]: qt.qml.typeregistration: Invalid QML element name "Hint"; value type names should begin with a lowercase letter
déc. 17 00:08:19 debian systemsettings[2212]: Failed to load vulkan: Impossible de charger la bibliothèque vulkan : vulkan: Ne peut ouvrir le fichier d'objet partagé: Aucun fichier ou dossier de ce nom
déc. 17 00:08:19 debian systemsettings[2212]: initInstance: No Vulkan library available
déc. 17 00:08:19 debian systemsettings[2212]: Failed to create platform Vulkan instance
déc. 17 00:08:19 debian systemsettings[2212]: Failed to create vulkan instance
déc. 17 00:08:19 debian systemsettings[2212]: GPU count mismatch (from vulkan). Are you maybe missing vulkan drivers? 0 1
...
éc. 17 00:08:21 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:08:21 debian plasmashell[1650]: kpipewire_logging: Failed to create PipeWire context
déc. 17 00:08:21 debian plasmashell[1650]: received error while creating the stream "Impossible de créer un contexte pour PipeWire" Media monitor will not work.
déc. 17 00:08:21 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:08:24 debian dbus-daemon[865]: [system] Activating service name='org.kde.kinfocenter.dmidecode' requested by ':1.76' (uid=1000 pid=2212 comm="/usr/bin/systemsettings kcm_about-distro") (using servicehelper)
déc. 17 00:08:24 debian org.kde.kinfocenter.dmidecode[2246]: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8.
Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead.
If this causes problems, reconfigure your locale. See the locale(1) manual
for more information.
...
déc. 17 00:08:21 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:08:21 debian plasmashell[1650]: kpipewire_logging: Failed to create PipeWire context
déc. 17 00:08:21 debian plasmashell[1650]: received error while creating the stream "Impossible de créer un contexte pour PipeWire" Media monitor will not work.
déc. 17 00:08:21 debian plasmashell[1650]: pw.conf: can't load config client.conf: Aucun fichier ou dossier de ce nom
déc. 17 00:08:24 debian dbus-daemon[865]: [system] Activating service name='org.kde.kinfocenter.dmidecode' requested by ':1.76' (uid=1000 pid=2212 comm="/usr/bin/systemsettings kcm_about-distro") (using servicehelper)
déc. 17 00:08:24 debian org.kde.kinfocenter.dmidecode[2246]: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8.
Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead.
If this causes problems, reconfigure your locale. See the locale(1) manual
for more information.
Et en PJ l’extraction complète des logs à partir du démarrage de la VM.
Si quelqu’un trouve des indices intéressant dans cette jungle 
export-logs-from-boot-20251216-rename.txt (220,6 Ko)