VNC超过lightdm会导致空白屏幕

Question

我正在尝试在lightdm上设置VNC，这样多个用户就可以登录到服务器，并且每个用户都有自己的会话。我使用Windows从TightVNC机器连接到Ubuntu虚拟机(服务器上的VMware)。统一的问候显示，我可以输入我的凭证，但那样的桌面就不会加载，我得到的只是一个空白的屏幕与墙纸。我也尝试了轻型gtk-问候，有同样的结果。

这是我的/etc/lightdm/lightdm.conf：

[SeatDefaults]
allow-guest=false
greeter-hide-users=true
greeter-show-manual-login=true
autologin-guest=false
# More sessions at /usr/share/xsessions/
user-session=gnome-fallback
# More greeters at /usr/share/xgreeters/
# greeter-session=lightdm-gtk-greeter
greeter-session=unity-greeter
[XDMCPServer]
enabled=true
port=177
[VNCServer]
enabled=true
command=/usr/bin/Xvnc -rfbauth /etc/vncpasswd
port=5900
width=1280
height=1024
depth=24

请注意用户会话:我正在尝试登录到gnome-回退会话。团结的人确实有Gnome的预选。我也尝试了其他条目(例如，Gnome )，结果也是一样。

错误记录在~/..xsession中-错误：

X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  109 (X_ChangeHosts)
  Value in failed request:  0x5
  Serial number of failed request:  6
  Current serial number in output stream:  8
X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  109 (X_ChangeHosts)
  Value in failed request:  0x5
  Serial number of failed request:  6
  Current serial number in output stream:  8
Script for ibus started at run_im.
Script for auto started at run_im.
Script for default started at run_im.
init: gpg-agent post-stop process (4335) killed by TERM signal
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd respawning too fast, stopped
init: unity-settings-daemon main process (4382) terminated with status 1
init: unity-settings-daemon main process ended, respawning
init: gnome-session (Unity) main process (4391) terminated with status 1
init: unity-settings-daemon main process (4573) killed by TERM signal
init: Disconnected from notified D-Bus bus

在“迎接者”中输入凭据后，/var/log/lightdm/lightdm.log中的消息：

[+971.31s] DEBUG: Session pid=5164: Continue authentication
[+971.92s] DEBUG: Session pid=5220: Authentication complete with return value 0: Success
[+971.92s] DEBUG: Session pid=5164: Authenticate result for user pamberg: Success
[+971.92s] DEBUG: Session pid=5164: User pamberg authorized
[+971.93s] DEBUG: Session pid=5164: Greeter requests default session
[+971.93s] DEBUG: Seat: Stopping greeter; display server will be re-used for user session
[+971.93s] DEBUG: Session pid=5164: Sending SIGTERM
[+971.95s] DEBUG: Session pid=5164: Exited with return value 0
[+971.95s] DEBUG: Seat: Session stopped
[+971.95s] DEBUG: Seat: Greeter stopped, running session
[+971.95s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+971.99s] DEBUG: Session pid=5220: Not setting XDG_VTNR
[+972.00s] DEBUG: Session pid=5220: Running command /usr/sbin/lightdm-session /usr/lib/gnome-panel/gnome-session-flashback
[+972.00s] DEBUG: Creating shared data directory /var/lib/lightdm-data/pamberg
[+972.00s] DEBUG: Session pid=5220: Logging to .xsession-errors
[+972.08s] DEBUG: Activating login1 session c13
[+972.12s] WARNING: Error activating login1 session: GDBus.Error:org.freedesktop.DBus.Error.Failed: Operation not supported

有什么想法吗？

Answer 1

听起来像这个问题：https://bugs.launchpad.net/lightdm/+bug/1420558。简而言之，LightDM的AppArmor策略没有考虑到VNC (截至Ubuntu14.04.2LTS)。

尝试删除/etc/apparmor.d/lightdm-guest-session。