Installed my Pi 3B+ with Ubuntu 18.04 per these instructions:
https://mega.nz/#!bCRzAawR!w4E_R4R89eLZ ... BPMVoqvwLY
Installed tasksel, then installed LAMP, removed Basic Server and Cloud Services. Added swap file.
Installed Zoneminder 1.32.3 per the WIKI install script:
https://wiki.zoneminder.com/Ubuntu_Serv ... e_easy_way
When adding a camera set Save JPEGs to Frames only and Video Writer to Disabled.
While this works it seems much slower than Raspbian with ZM 1.30.4. I might just drop back to 1.30.4 on this Pi Ubuntu install.
Tip: When you get Ubuntu set up on your MicroSD card use Clonezilla and a card reader in another PC to make an image of the card. Very easy to go back if you want to start over...