Does installing desktop on Ubuntu Server turn it into the desktop version?

[Bo Berglund]

I would like to know what is expected to happen when you have an Ubuntu Server
20.04.3 and install a desktop environment into it.

I have been experimenting in a virtual machine environment for a number of hours
now and I do not understand some of what I have seen.

I used the snapshot facility of VMWare Workstation to be able to return to the
same state after doing modifications.

First I installed Ubuntu Server 20.04.3 LTS from the downloaded server ISO into
a new virtual machine where I had configured a 40 GB virtual drive.

Once all of that was done I wound up with this base state (snapshot BASE):
(edited out small /dev/&loop and tempfs stuff)

$ df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               1.9G     0  1.9G   0% /dev
tmpfs                              391M  1.6M  390M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   20G  6.3G   13G  34% /
tmpfs                              2.0G     0  2.0G   0% /sys/fs/cgroup
/dev/sda2                          976M  107M  803M  12% /boot


Then I installed KDE using
sudo apt install kde-standard

After it was all done and I had logged in I got this (snapshot KDE):

$ df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               1.9G     0  1.9G   0% /dev
tmpfs                              391M  1.6M  390M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   20G  8.3G   11G  45% /
tmpfs                              2.0G     0  2.0G   0% /dev/shm
/dev/sda2                          976M  107M  803M  12% /boot

And after installing MATE using:
sudo apt install ubuntu-mate-desktop

I got this (snapshot MATE):

$ df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               1.9G     0  1.9G   0% /dev
tmpfs                              391M  1.8M  390M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   20G  9.4G  9.3G  51% /
tmpfs                              2.0G     0  2.0G   0% /dev/shm
/dev/sda2                          976M  112M  798M  13% /boot

And lastly I also tried the Cinnamon desktop with this command:
sudo apt install cinnamon-desktop-environment

I now got this (snapshot Cinnamon):

~$ df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               1.9G     0  1.9G   0% /dev
tmpfs                              391M  1.7M  390M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   20G  9.8G  8.9G  53% /
tmpfs                              2.0G     0  2.0G   0% /dev/shm
/dev/sda2                          976M  107M  803M  12% /boot

To summarize the disk usage:

Base server  6.3 GB
KDE          8.3 GB
MATE         9.3 GB
Cinnamon     9.8 GB

So the add-on disk usage turned out to be 2.0, 3.0 and 3.5 GB respectively and
all except KDE sported Office, Video, Audio, Games and Graphics applications....

KDE looked really strange too, nothing I would like to use.

So now I wonder if I install any of Mate or Cinnamon on the real server will it
then have been transformed into the desktop version one gets if installing from
the desktop ISO?
I can use either of them since they look like they are sensibly designed
desktops.

Is there any reason to select either over the other?

Another question after inspecting my disk from the Cinnamon desktop using
Gparted (had to be installed first):
In GParted I see only 3 partitions taking up all 40GB of disk space:

/dev/sda1    grub.core.img                1.00 MiB
/dev/sda2             ext4  /boot         1.00 GiB
/dev/sda3          lvm2 pv  ubuntu-vg    39.00 GiB

I have a hard time figuring out the mapping between what df -h shows and what
GParted shows...
Why is the partition holding / shown at different sizes in these views?
Only about half of what is there seems to be available...

The /etc/fstab file looks like this:

/dev/disk/by-id/dm-uuid-LVM-Z3uK3zYox...3onmrLk0K6QDoiX / ext4 defaults 0 1
# /boot was on /dev/sda2 during curtin installation
/dev/disk/by-uuid/06b664e5-ddb6-4eff-94d2-a27...cea /boot ext4 defaults 0 1
/swap.img       none    swap    sw      0       0



-- 
Bo Berglund
Developer in Sweden