Bonjour.
Il semblerait que Virt-Manager (ou libvirtd) ne fonctionne pas avec les kernels post-installation.
En effet, sur une install fraiche, aucun problème.
Par contre, si j'utilise un autre kernel, j'obtiens ce doux message au lancement de Virt-manager :
Impossible de se connecter à libvirt.

Vérifiez que le démon « libvirtd » est en cours d'exécution.

Libvirt URI is: qemu:///system

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/connection.py", line 1027, in _open_thread
    self.vmm = self._try_open()
  File "/usr/share/virt-manager/virtManager/connection.py", line 1009, in _try_open
    flags)
  File "/usr/lib64/python2.7/site-packages/libvirt.py", line 102, in openAuth
    if ret is None:raise libvirtError('virConnectOpenAuth() failed')
libvirtError: Failed to connect socket to '/var/run/libvirt/libvirt-sock': Aucun fichier ou dossier de ce type
[root@VaioLaptop quentin]# systemctl
UNIT                                                                                     LOAD   ACTIVE SUB       JOB DESCRIPTION
proc-sys-fs-binfmt_misc.automount                                                        loaded active waiting       Arbitrary Executable File Formats File System Automount Point
sys-devices-pci0000:00-0000:00:01.0-0000:01:00.1-sound-card1.device                      loaded active plugged       GF108 High Definition Audio Controller
sys-devices-pci0000:00-0000:00:1b.0-sound-card0.device                                   loaded active plugged       6 Series/C200 Series Chipset Family High Definition Audio Controller
sys-devices-pci0000:00-0000:00:1c.0-0000:02:00.0-net-wlan0.device                        loaded active plugged       AR9485 Wireless Network Adapter
sys-devices-pci0000:00-0000:00:1c.3-0000:05:00.0-net-p3p1.device                         loaded active plugged       RTL8111/8168B PCI Express Gigabit Ethernet controller
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda1.device loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda2.device loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda3.device loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda4.device loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda5.device loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda6.device loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda7.device loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda-sda8.device loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata1-host0-target0:0:0-0:0:0:0-block-sda.device      loaded active plugged       ST95005620AS
sys-devices-pci0000:00-0000:00:1f.2-ata5-host4-target4:0:0-4:0:0:0-block-sr0.device      loaded active plugged       MATSHITADVD-RAM_UJ8B0
sys-devices-platform-serial8250-tty-ttyS0.device                                         loaded active plugged       /sys/devices/platform/serial8250/tty/ttyS0
sys-devices-platform-serial8250-tty-ttyS1.device                                         loaded active plugged       /sys/devices/platform/serial8250/tty/ttyS1
sys-devices-platform-serial8250-tty-ttyS2.device                                         loaded active plugged       /sys/devices/platform/serial8250/tty/ttyS2
sys-devices-platform-serial8250-tty-ttyS3.device                                         loaded active plugged       /sys/devices/platform/serial8250/tty/ttyS3
sys-module-configfs.device                                                               loaded active plugged       /sys/module/configfs
sys-subsystem-net-devices-p3p1.device                                                    loaded active plugged       RTL8111/8168B PCI Express Gigabit Ethernet controller
sys-subsystem-net-devices-wlan0.device                                                   loaded active plugged       AR9485 Wireless Network Adapter
-.mount                                                                                  loaded active mounted       /
dev-hugepages.mount                                                                      loaded active mounted       Huge Pages File System                                                                          
dev-mqueue.mount                                                                         loaded active mounted       POSIX Message Queue File System
home.mount                                                                               loaded active mounted       /home
sys-kernel-config.mount                                                                  loaded active mounted       Configuration File System
sys-kernel-debug.mount                                                                   loaded active mounted       Debug File System
tmp.mount                                                                                loaded active mounted       Temporary Directory
cups.path                                                                                loaded active waiting       CUPS Printer Service Spool
systemd-ask-password-plymouth.path                                                       loaded active waiting       Forward Password Requests to Plymouth Directory Watch
systemd-ask-password-wall.path                                                           loaded active waiting       Forward Password Requests to Wall Directory Watch
abrt-ccpp.service                                                                        loaded active exited        Install ABRT coredump hook
abrt-oops.service                                                                        loaded active running       ABRT kernel log watcher
abrt-vmcore.service                                                                      loaded active exited        Harvest vmcores for ABRT
abrt-xorg.service                                                                        loaded active running       ABRT Xorg log watcher
abrtd.service                                                                            loaded active running       ABRT Automated Bug Reporting Tool
accounts-daemon.service                                                                  loaded active running       Accounts Service
atd.service                                                                              loaded active running       Job spooling tools
auditd.service                                                                           loaded active running       Security Auditing Service
bluetooth.service                                                                        loaded active running       Bluetooth service
chronyd.service                                                                          loaded active running       NTP client/server
colord.service                                                                           loaded active running       Manage, Install and Generate Color Profiles
console-kit-daemon.service                                                               loaded active running       Console Manager
console-kit-log-system-start.service                                                     loaded active exited        Console System Startup Logging
crond.service                                                                            loaded active running       Command Scheduler
cups.service                                                                             loaded active running       CUPS Printing Service
dbus.service                                                                             loaded active running       D-Bus System Message Bus
fedora-loadmodules.service                                                               loaded active exited        Load legacy module configuration
fedora-readonly.service                                                                  loaded active exited        Configure read-only root support
fedora-storage-init-late.service                                                         loaded active exited        Initialize storage subsystems (RAID, LVM, etc.)
fedora-storage-init.service                                                              loaded active exited        Initialize storage subsystems (RAID, LVM, etc.)
firewalld.service                                                                        loaded active running       firewalld - dynamic firewall daemon
irqbalance.service                                                                       loaded active running       irqbalance daemon
iscsi.service                                                                            loaded active exited        LSB: Starts and stops login and scanning of iSCSI devices.
iscsid.service                                                                           loaded active running       LSB: Starts and stops login iSCSI daemon.
ksm.service                                                                              loaded active exited        Kernel Samepage Merging
ksmtuned.service                                                                         loaded active running       Kernel Samepage Merging (KSM) Tuning Daemon
libvirtd.service                                                                         loaded failed failed        Virtualization daemon
lightdm.service                                                                          loaded active running       Light Display Manager
lvm2-monitor.service                                                                     loaded active exited        Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling
mcelog.service                                                                           loaded active running       Machine Check Exception Logging Daemon
mdmonitor-takeover.service                                                               loaded active exited        Software RAID Monitor Takeover
NetworkManager.service                                                                   loaded active running       Network Manager
polkit.service                                                                           loaded active running       Authorization Manager
rngd.service                                                                             loaded failed failed        Hardware RNG Entropy Gatherer Daemon
rpcbind.service                                                                          loaded active running       RPC bind service
rsyslog.service                                                                          loaded active running       System Logging Service
rtkit-daemon.service                                                                     loaded active running       RealtimeKit Scheduling Policy Service
sendmail.service                                                                         loaded active running       Sendmail Mail Transport Agent
sm-client.service                                                                        loaded active running       Sendmail Mail Transport Client
smartd.service                                                                           loaded active running       Self Monitoring and Reporting Technology (SMART) Daemon
sshd.service                                                                             loaded active running       OpenSSH server daemon
systemd-journald.service                                                                 loaded active running       Journal Service
systemd-logind.service                                                                   loaded active running       Login Service
systemd-modules-load.service                                                             loaded active exited        Load Kernel Modules
systemd-readahead-collect.service                                                        loaded active exited        Collect Read-Ahead Data
systemd-readahead-replay.service                                                         loaded active exited        Replay Read-Ahead Data
systemd-remount-fs.service                                                               loaded active exited        Remount Root and Kernel File Systems
systemd-sysctl.service                                                                   loaded active exited        Apply Kernel Variables
systemd-tmpfiles-setup.service                                                           loaded active exited        Recreate Volatile Files and Directories
systemd-udev-settle.service                                                              loaded active exited        udev Wait for Complete Device Initialization
systemd-udev-trigger.service                                                             loaded active exited        udev Coldplug all Devices
systemd-udevd.service                                                                    loaded active running       udev Kernel Device Manager
systemd-user-sessions.service                                                            loaded active exited        Permit User Sessions
systemd-vconsole-setup.service                                                           loaded active exited        Setup Virtual Console
udisks2.service                                                                          loaded active running       Disk Manager
upower.service                                                                           loaded active running       Daemon for power management
wpa_supplicant.service                                                                   loaded active running       WPA Supplicant daemon
cups.socket                                                                              loaded active running       CUPS Printing Service Sockets
dbus.socket                                                                              loaded active running       D-Bus System Message Bus Socket
dm-event.socket                                                                          loaded active listening     Device-mapper event daemon FIFOs
lvm2-lvmetad.socket                                                                      loaded active listening     LVM2 metadata daemon socket
pcscd.socket                                                                             loaded active listening     PC/SC Smart Card Daemon Activation Socket
rpcbind.socket                                                                           loaded active listening     RPCbind Server Activation Socket
syslog.socket                                                                            loaded active running       Syslog Socket
systemd-initctl.socket                                                                   loaded active listening     /dev/initctl Compatibility Named Pipe
systemd-journald.socket                                                                  loaded active running       Journal Socket
systemd-shutdownd.socket                                                                 loaded active listening     Delayed Shutdown Socket
systemd-udevd-control.socket                                                             loaded active running       udev Control Socket
systemd-udevd-kernel.socket                                                              loaded active running       udev Kernel Socket
basic.target                                                                             loaded active active        Basic System
cryptsetup.target                                                                        loaded active active        Encrypted Volumes
getty.target                                                                             loaded active active        Login Prompts
graphical.target                                                                         loaded active active        Graphical Interface
initrd-switch-root.target                                                                loaded active active        Switch Root
local-fs-pre.target                                                                      loaded active active        Local File Systems (Pre)
local-fs.target                                                                          loaded active active        Local File Systems
multi-user.target                                                                        loaded active active        Multi-User
network.target                                                                           loaded active active        Network
remote-fs.target                                                                         loaded active active        Remote File Systems
sockets.target                                                                           loaded active active        Sockets
sound.target                                                                             loaded active active        Sound Card
swap.target                                                                              loaded active active        Swap
sysinit.target                                                                           loaded active active        System Initialization
syslog.target                                                                            loaded active active        Syslog
systemd-readahead-done.timer                                                             loaded active elapsed       Stop Read-Ahead Data Collection 10s After Completed Startup
systemd-tmpfiles-clean.timer                                                             loaded active waiting       Daily Cleanup of Temporary Directories

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.
JOB    = Pending job for the unit.

118 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.
(END)
En effet, l'activation de libvirtd a échoué.
Avez vous une idée de comment solutionner ce problème ?
Merci d'avance pour votre aide.
Faut faire un bug report dans ces cas là ? 😃
[root@VaioLaptop quentin]# systemctl status libvirtd
libvirtd.service - Virtualization daemon
          Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled)
          Active: failed (Result: exit-code) since Fri, 2013-01-18 23:38:50 CET; 7min ago
         Process: 8183 ExecStart=/usr/sbin/libvirtd $LIBVIRTD_ARGS (code=exited, status=1/FAILURE)
          CGroup: name=systemd:/system/libvirtd.service

Jan 18 23:38:50 VaioLaptop systemd[1]: Starting Virtualization daemon...
Jan 18 23:38:50 VaioLaptop systemd[1]: Started Virtualization daemon.
Jan 18 23:38:50 VaioLaptop libvirtd[8183]: /usr/sbin/libvirtd: initialization failed
Jan 18 23:38:50 VaioLaptop systemd[1]: libvirtd.service: main process exited, code=exited, status=1/FAILURE
Jan 18 23:38:50 VaioLaptop systemd[1]: Unit libvirtd.service entered failed state
Le problème est contourné, #/usr/sbin/libvirtd et #libvirtd fonctionnent tous deux :
^C[root@VaioLaptop quentin]# /usr/sbin/libvirtd
2013-01-19 15:26:17.223+0000: 5142: info : libvirt version: 0.10.2.2, package: 3.fc18 (Fedora Project, 2012-12-17-23:55:54, buildvm-14.phx2.fedoraproject.org)
2013-01-19 15:26:17.223+0000: 5142: warning : virGetHostname:2265 : getaddrinfo failed for 'VaioLaptop': Nom ou service inconnu
^C[root@VaioLaptop quentin]# libvirtd
2013-01-19 15:26:21.497+0000: 5178: info : libvirt version: 0.10.2.2, package: 3.fc18 (Fedora Project, 2012-12-17-23:55:54, buildvm-14.phx2.fedoraproject.org)
2013-01-19 15:26:21.497+0000: 5178: warning : virGetHostname:2265 : getaddrinfo failed for 'VaioLaptop': Nom ou service inconnu
2013-01-19 15:26:21.809+0000: 5189: info : libvirt version: 0.10.2.2, package: 3.fc18 (Fedora Project, 2012-12-17-23:55:54, buildvm-14.phx2.fedoraproject.org)
2013-01-19 15:26:21.809+0000: 5189: error : virCommandWait:2287 : erreur interne Child process (/usr/bin/firewall-cmd --direct --passthrough ipv4 --table nat --delete POSTROUTING --source 192.168.122.0/24 -p tcp '!' --destination 192.168.122.0/24 --jump MASQUERADE --to-ports 1024-65535) unexpected exit status 13
2013-01-19 15:26:21.934+0000: 5189: error : virCommandWait:2287 : erreur interne Child process (/usr/bin/firewall-cmd --direct --passthrough ipv4 --table nat --delete POSTROUTING --source 192.168.122.0/24 -p udp '!' --destination 192.168.122.0/24 --jump MASQUERADE --to-ports 1024-65535) unexpected exit status 13
2013-01-19 15:26:22.054+0000: 5189: error : virCommandWait:2287 : erreur interne Child process (/usr/bin/firewall-cmd --direct --passthrough ipv4 --table nat --delete POSTROUTING --source 192.168.122.0/24 '!' --destination 192.168.122.0/24 --jump MASQUERADE) unexpected exit status 13
2013-01-19 15:26:22.176+0000: 5189: error : virCommandWait:2287 : erreur interne Child process (/usr/bin/firewall-cmd --direct --passthrough ipv4 --table filter --delete FORWARD --destination 192.168.122.0/24 --out-interface virbr0 --match state --state ESTABLISHED,RELATED --jump ACCEPT) unexpected exit status 13
2013-01-19 15:26:22.287+0000: 5189: error : virCommandWait:2287 : erreur interne Child process (/usr/bin/firewall-cmd --direct --passthrough ipv4 --table filter --delete FORWARD --source 192.168.122.0/24 --in-interface virbr0 --jump ACCEPT) unexpected exit status 13
J'imagine que c'est le warning qui empêche le service systemd de se lancer ...
edit :
Le problème getaddrinfo a été résolu en éditant /etc/hosts mais cela ne permet toujours pas de lancer libvirtd par systemctl.
Le problème semble résolu après cette MàJ (et quelques bidouilles grub)
[root@VaioLaptop quentin]# yum history info 54
Modules complémentaires chargés : langpacks, presto, refresh-packagekit
ID de transaction : 54
Temps de début    : Sat Jan 19 16:09:46 2013
Début de RPMDB    : 1422:119999087efb1ef54ed8a8c0f5b9aa3ef039ddf0
Temps de fin :            16:10:05 2013 (19 secondes)
Fin de RPMDB : 1422:fb9680096e66245aa3ea561d62e6066e897105f4
Utilisateur  : quentin <quentin>
Code retour  : Réussi
Transaction effectuée avec :
    Installé     rpm-4.10.2-1.fc18.x86_64                @updates
    Installé     yum-3.4.3-47.fc18.noarch                @fedora
    Installé     yum-metadata-parser-1.1.4-7.fc18.x86_64 @fedora
    Installé     yum-presto-0.9.0-1.fc18.noarch          @fedora
    Installé     yumex-3.0.10-1.fc18.noarch              @fedora
Paquets modifiés :
    Mis à jour  apper-0.8.0-0.11.20121126git.fc18.x86_64    @fedora
    Mise à jour       0.8.0-2.fc18.x86_64                   @updates
    Mis à jour  brlapi-0.5.6-10.fc18.x86_64                 @updates
    Mise à jour        0.5.6-12.fc18.x86_64                 @updates
    Mis à jour  brltty-4.3-10.fc18.x86_64                   @updates
    Mise à jour        4.3-12.fc18.x86_64                   @updates
    Mis à jour  firewall-config-0.2.11-2.fc18.noarch        @fedora
    Mise à jour                 0.2.12-1.fc18.noarch        @updates
    Mis à jour  firewalld-0.2.11-2.fc18.noarch              @fedora
    Mise à jour           0.2.12-1.fc18.noarch              @updates
    Mis à jour  libcdr-0.0.8-2.fc18.x86_64                  @fedora
    Mise à jour        0.0.9-2.fc18.x86_64                  @updates
    Mis à jour  lsof-4.86-4.fc18.x86_64                     @fedora
    Mise à jour      4.87-1.fc18.x86_64                     @updates
    Mis à jour  nmap-ncat-2:6.01-8.fc18.x86_64              @fedora
    Mise à jour           2:6.01-9.fc18.x86_64              @updates
    Mis à jour  system-config-language-1.3.5-14.fc18.noarch @fedora
    Mise à jour                        1.3.5-19.fc18.noarch @updates
history info
[root@VaioLaptop quentin]# systemctl status libvirtd
libvirtd.service - Virtualization daemon
          Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled)
          Active: active (running) since Sat, 2013-01-19 23:48:29 CET; 1min 34s ago
        Main PID: 1117 (libvirtd)
          CGroup: name=systemd:/system/libvirtd.service
                  ├ 1117 /usr/sbin/libvirtd
                  └ 1239 /sbin/dnsmasq --strict-order --local=// --domain-needed --pid-file=/var/run/libvirt/network/default.pid --conf-file= --except-interface lo --bind-dynamic --interface virbr0 --dhcp-ran...

Jan 19 23:48:31 VaioLaptop dnsmasq[1239]: using local addresses only for unqualified names
Jan 19 23:48:31 VaioLaptop dnsmasq[1239]: read /etc/hosts - 3 addresses
Jan 19 23:48:31 VaioLaptop dnsmasq[1239]: read /var/lib/libvirt/dnsmasq/default.addnhosts - 0 addresses
Jan 19 23:48:31 VaioLaptop dnsmasq-dhcp[1239]: read /var/lib/libvirt/dnsmasq/default.hostsfile
Jan 19 23:48:33 VaioLaptop dnsmasq[1239]: reading /etc/resolv.conf
Jan 19 23:48:33 VaioLaptop dnsmasq[1239]: using nameserver 2a01:e00::1#53
Jan 19 23:48:33 VaioLaptop dnsmasq[1239]: using nameserver 2a01:e00::2#53
Jan 19 23:48:33 VaioLaptop dnsmasq[1239]: using nameserver 212.27.40.241#53
Jan 19 23:48:33 VaioLaptop dnsmasq[1239]: using nameserver 212.27.40.240#53
Jan 19 23:48:33 VaioLaptop dnsmasq[1239]: using local addresses only for unqualified names