LUKS is a standard for Linux hard disk encryption. By providing a standard on-disk-format, it does not only facilitate compatibility among distributions, but also provides secure management of multiple user passwords. LUKS stores all necessary setup information in the partition header, enabling the user to transport or migrate data seamlessly
The Ubuntu installer seems to be quite willing to kill LUKS containers in several different ways, so treat the process of installing Ubuntu as a severe hazard to any LUKS container you may have