I used the methods described in this page and this one to connect to the Amazon EC2 ubuntu instance using remote desktop. But I always got a grey background shown in this image: 
The log file in ~/.vnc:
21/12/14 04:20:23 Got connection from client 127.0.0.1
21/12/14 04:20:23 Using protocol version 3.8
21/12/14 04:20:23 Full-control authentication passed by 127.0.0.1
21/12/14 04:20:23 Pixel format for client 127.0.0.1:
21/12/14 04 20:23 8 bpp, depth s
21/12/14 04:20:23 true colour: max r 7 g 7 b 3, shift r 0 g 3 b 6
21/12/14 04:20:23 Using tight encoding for client 127.0.0.1
21/12/14 04:20:23 rfbProcessClientNormalMessage: ignoring unknown encoding 16
21/12/14 04:20:23 rfbProcessClientNormalMessage: ignoring unknown encoding 9
21/12/14 04:20:23 rfbProcessClientNormalMessage: ignoring unknown encoding -65527
21/12/14 04:20:23 Using compression level 9 for client 127.0.0.1
21/12/14 04:20:23 Using image quality level 0 for client 127.0.0.1
21/12/14 04:20:23 Enabling X-style cursor updates for client 127.0.0.1
21/12/14 04:20:23 Enabling cursor position updates for client 127.0.0.1
21/12/14 04:20:23 rfbProcessClientNormalMessage: ignoring unknown encoding -131072
21/12/14 04:20:23 rfbProcessClientNormalMessage: ignoring unknown encoding -223
21/12/14 04:20:23 Enabling LastRect protocol extension for client 127.0.0.1
21/12/14 04:20:23 rfbProcessClientNormalMessage: ignoring unknown encoding -131071
21/12/14 04:20:23 rfbProcessClientNormalMessage: ignoring unknown encoding -131070
21/12/14 04:20:23 rfbProcessClientNormalMessage: ignoring unknown encoding -131069
21/12/14 04:20:38 KbdAddEvent: unknown KeySym 0xff15 - allocating KeyCode 89
The contents of .vnc/xstartup is:
#!/bin/sh
# Uncomment the following two lines for normal desktop:
#unset SESSION_MANAGER
#exec sh /etc/X11/xinit/xinitrc
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
gnome-session &
The contents of the log file is:
22/12/14 15:33:42 Xvnc version TightVNC-1.3.9
22/12/14 15:33:42 Copyright (C) 2000-2007 TightVNC Group
22/12/14 15:33:42 Copyright (C) 1999 AT&T Laboratories Cambridge
22/12/14 15:33:42 All Rights Reserved.
22/12/14 15:33:42 See http://www.tightvnc.com/ for information on TightVNC
22/12/14 15:33:42 Desktop name 'X' (ip-172-31-21-231:1)
22/12/14 15:33:42 Protocol versions supported: 3.3, 3.7, 3.8, 3.7t, 3.8t
22/12/14 15:33:42 Listening for VNC connections on TCP port 5901
Font directory '/usr/share/fonts/X11/75dpi/' not found - ignoring
Font directory '/usr/share/fonts/X11/100dpi/' not found - ignoring
No VNC extension on display :1
Option "--login" is no longer supported in this version of gnome-terminal; you might want to create a profile with the desired setting, and use the new '--profile' option
gnome-session-is-accelerated: No composite extension.
gnome-session-check-accelerated: Helper exited with code 256
(gnome-terminal:3848): GLib-GIO-CRITICAL **: g_settings_get: the format string may not contain '&' (key 'monospace-font-name' from schema 'org.gnome.desktop.interface'). This call will probably stop working with a future version of glib.
gnome-session-is-accelerated: No composite extension.
gnome-session-check-accelerated: Helper exited with code 256
** (process:3849): WARNING **: software acceleration check failed: Child process exited with code 1
** (gnome-session:3849): CRITICAL **: We failed, but the fail whale is dead. Sorry....
22/12/14 15:33:53 Got connection from client *.*.5.179
22/12/14 15:33:54 Using protocol version 3.8
22/12/14 15:33:54 Enabling TightVNC protocol extensions
22/12/14 15:33:56 Full-control authentication passed by *.*.5.179
22/12/14 15:33:56 Using tight encoding for client *.*.5.179
22/12/14 15:33:56 rfbProcessClientNormalMessage: ignoring unknown encoding 16
22/12/14 15:33:56 rfbProcessClientNormalMessage: ignoring unknown encoding -223
22/12/14 15:33:56 Enabling LastRect protocol extension for client *.*.5.179
22/12/14 15:33:56 Enabling cursor position updates for client *.*.5.179
22/12/14 15:33:56 Enabling full-color cursor updates for client *.*.5.179
From the log file we can see there is an error "CRITICAL **: We failed, but the fail whale is dead. Sorry....". I wonder if it is the reason for unity's not appearing.
Could anyone please help me with this problem?
Follow-up: I followed the steps in this article, but the screen now becomes the one in this image: tinypic.com/r/2mnm4vm/8 -- there is no unity desktop.
