I've installed Ubuntu server 10.04 and then installed Gnome desktop on top of it, because I am new to Linux and its command line, I need the GUI desktop to help me get around. However, the problem I got is that the server doesn't boot into the GUI desktop when powered on. It's booting into a shell like this:

Gave up waiting for root device.  Common problems:
 - Boot args (cat /proc/cmdline)
   - Check rootdelay= (did the system wait long enought?)
   - check root= (did the system wait for the right device?)
 - Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/mapper/cecdata-root does not exist. Dropping to a shell!

BusyBox v1.13.3 (Ubuntu 1:1.13.3-1ubuntu11) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs)

result of (cat /proc/cmdline)
BOOT_IMAGE=/vmlinuz-2.6.32-28-server root=/dev/mapper/cecdata-root ro quiet

Then I have type "exit" to exit the shell and then it boots into Gnome. Any idea what's wrong?

Edit: add output for the following commands

wt@cecdata:~$ ls /dev/mapper/
cecdata-root  cecdata-swap_1  control

wt@cecdata:~$ fdisk -l
wt@cecdata:~$

wt@cecdata:~$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    nodev,noexec,nosuid 0       0
/dev/mapper/cecdata-root /               ext4    errors=remount-ro 0       1
# /boot was on /dev/sda1 during installation
UUID=1635be41-d025-405e-b4a3-6f0abedb7aab /boot           ext2    defaults        0       2
/dev/mapper/cecdata-swap_1 none            swap    sw              0       0
wt@cecdata:~$

Adding output for lsmod

wt@cecdata:~$ lsmod
Module                  Size  Used by
fbcon                  39270  71
tileblit                2487  1 fbcon
font                    8053  1 fbcon
bitblit                 5811  1 fbcon
softcursor              1565  1 bitblit
dell_wmi                2177  0
dcdbas                  6918  0
vga16fb                12757  1
vgastate                9857  1 vga16fb
psmouse                64576  0
serio_raw               4950  0
power_meter             9473  0
bnx2                   72874  0
lp                      9336  0
parport                37160  1 lp
mptsas                 50592  2
usbhid                 41116  0
mptscsih               37167  1 mptsas
hid                    83568  1 usbhid
mptbase                91674  2 mptsas,mptscsih
scsi_transport_sas     33021  1 mptsas