Upgraded 14.04 to 16.04 rebooted - got the option to resize - took that, allowed the minimum.
Rebooted again to clean install and then got the option to install alongside a second time (screenshot)
Clean install - got option to resize.
Not seeing this on Xubuntu.
Ftr - vm is set to use 2048Mb Ram - consequently installer is creating a swp partion of the same size, so effectively managing to see the option to install 3 xubuntu's on 18Gb.
Using a 20Gb vm I have:
Upgraded 14.04 to 16.04 rebooted - got the option to resize - took that, allowed the minimum.
Rebooted again to clean install and then got the option to install alongside a second time (screenshot)
Clean install - got option to resize.
Not seeing this on Xubuntu.
Ftr - vm is set to use 2048Mb Ram - consequently installer is creating a swp partion of the same size, so effectively managing to see the option to install 3 xubuntu's on 18Gb.