What is the difference between Ubuntu Server and Ubuntu Server Live?

Solution 1:

You are referring to the difference between the two server installer images:

• ubuntu-18.04.1-live-server-amd64.iso
  Server install image for 64-bit PC (AMD64) computers (standard download) and
• ubuntu-18.04.1-server-amd64.iso
  that also has versions for for different platforms: 64-bit ARM, PowerPC64 and IBM System z.

The difference is in the installers, and it's explained in BionicBeaver Release Notes:

The next generation Subiquity server installer, brings the comfortable live session and speedy install of Ubuntu Desktop to server users at last.

N.B., If you require multipath, full-disk encryption, or the ability to re-using existing partitions, you will want to continue to use the alternate installer which can be downloaded from http://cdimage.ubuntu.com/releases/18.04/release/

As of 18.04.1, the Subiquity server installer now supports LVM, RAID, vlans, and bonds.

According to Ubuntu forums, there are also more differences between 18.04 "live" and "alternative":

1. Changing the hostname will revert back to the original name after reboot on an install using "live" unless the following is changed:

   Edit /etc/cloud/cloud.cfg and change preserve_hostname to true

2. On a "live" install, the following mount exists:

   /dev/loop0 88704 88704 0 100% /snap/core/4486
   

3. On the "live" install the settings for auto updates are in /etc/apt/apt.conf.d/20auto-upgrades while on "alternative" install they are in a different config file (just grep /etc for "Update-Package-Lists" string)

4. The "live" install asks the user on the first login to install a language pack:

   sudo apt-get install language-pack-en
   

5. The cloud-init package is not installed by default with the "alternative" ISO but it is with the "live" ISO.