How to install Ubuntu Server 14.04 on a Mac

We have an old Mac tower in the office that I've been using as a headless server, and last time around I couldn't even get 12.04 server to install - I needed to install 12.04 desktop.

This time around, the Ubuntu server 14.04 install works fine... except it hangs at boot

Looking at the output, it has an issue with plymouth-upstart-bridge, then tries to mount swap, and then it does nothing...

I came across this post that had the answer - booting will work if you boot in recovery mode (grub -> advanced options -> ubuntu recovery) and then resume the boot. The permanent fix is to add "nomodeset" to grub.

Instructions from the beginning

1. Copy ubuntu 14.04 amd64 server iso onto a USB drive (sudo dd if=ubuntu-14.04-server-amd64.iso of=/dev/sdX bs=1M) (*don't blame me* if you accidentally override your main harddrive)
2. Plug usb key into server, boot up (if it doesn't boot off USB you may need to hold down ALT to get the magic screen and then choose EFI USB boot)
3. Run install like you normally would
4. Find that it hangs on boot
5. Boot again but in recovery mode (at GRUB choose "advanced options" and boot into recovery mode)
6. Log in
7. sudo vim /etc/default/grub
8. Edit the line GRUB_CMDLINE_LINUX_DEFAULT="" to say GRUB_CMDLINE_LINUX_DEFAULT="nomodeset"
9. Save file
10. sudo update-grub
11. Reboot
12. *magic it works yay*