There are two ways to initialise a new series:

In both cases, initialisation is done as a background task after the "Initialize Series" button is pressed.

Continuation series

This will copy all the sources and binaries from the previous series in the distribution. Its parent series default to the parent series used in the previous series, but they can be changed. This is useful, for example, when the new series has a longer support period and you wish to sync packages from a more stable upstream series. On an Ubuntu-sized distribution, expect the background task to complete in around 10 minutes.

It will also copy all of the settings from the previous series, such as upload permissions and packagesets.

New derived distribution series

Initializing a new distribution is a complicated task. It takes a long time and has a lot of checks. There are various things that you need to specify:

Normally you can expect the initialisation to complete in minutes if you have less than around 1000 packages, but it will non-linearly increase as the number of copied packages increases, because it has to check that you are not copying conflicting packages.

Pre-initialisation checks and errors