After installing Ubuntu Server 14.04 LTS, the OS appears to hang before reaching the login prompt on subsequent boot. It is actually just the display which fails to update. The root cause is lack of support for newer Nvidia cards in the open source Nouveau driver.
To work around this issue, perform the following steps when booting:
The system should then boot to the login prompt.
If the system will be used in text mode, perform the following steps to work around the problem for future reboots:
Open /etc/default/grub in an editor
Add the nomodeset option to the GRUB_CMDLINE_LINUX_DEFAULT entry:
GRUB_CMDLINE_LINUX_DEFAULT="nomodeset"
Update the GRUB boot loader
$ sudo update-grub
If the system will be used in GUI mode, perform the following steps:
Install the graphical desktop packages
$ sudo apt-get install ubuntu-desktop
Follow the Nvidia binary driver installation instructions