Ubuntu Server Install only uses half of availabe space for root partition

When installing using the 20.04 Ubuntu server installation media, with LVM (and encryption enabled), using the default full-disk setup. The installation only allocates half of the available space for the logical volume for the root filesystem.

Here is a screenshot from a VM, althought this also happens with physical hardware:

Why is this, and is there a way I can get the default to use the full disk (ex with cloudinit config).

Solution 1:

Apparently this was an intentional decision.

From https://bugs.launchpad.net/ubuntu/+source/subiquity/+bug/1907128 :

This is by design. There's not much point in using LVM if you then completely fill up the volume group with a single logical volume -- you can't take snapshots, for example -- and expanding a LV later is much easier than shrinking one.