I want to setup an Ubuntu server with LVM. I installed Ubuntu using ubuntu-12.04.1-alternate-amd64.iso because I believe that the "alternate" disc must be used to install with LVM. However it created an Ubuntu desktop for me. Where did I go wrong? Should I use the server iso or is there someplace in the alternate iso where I can change a setting to not install the desktop?
It makes no real difference if you use the alternate or server iso. IMHO is the only difference between desktop and server installation the set of installed packages. Since 2011(?) the special server kernel is dropped.
To install an ubuntu system with LVM you have to take attention at the partitioning step in the installer. This is the point where you introduce your LVM configuration selecting pysical volumnes, volumne group and logical volumnes.
After creating this assets you continue in the usual way assigning the logical volumnes in the same way as a traditional partition to a mountpoint.
As a little trick it can be useful to switch from the installer to the shell and invoke the necessary LVM commands inside the shell (e.g. copy&paste from your note-book).
No Server without underlying mdraid below the LVM layer. This will be a significant improvement to the data security (raid 1,5 or 6 assumed).