People interested in this topic should read the Kaiser's Holocaust.
Before the Germans started colonizing themselves they were the fiercest critics of genocidal violence by the Colonial empires. Ironically, the later Herrero and Nama genocide was largely justified by pointing to the United States and its strategies for dealing with Native Americans and the British concentration camps in the second Boer War as successful examples of counter-insurgency strategies to be emulated and improved upon.
The second interesting thing about this genocide is the connection between former colonial administrators (after Germany lost its colonies in WWI) and the Nazis. The brownshirts (SA) of the early Nazi party were literally wearing surplus colonial uniforms. Hermann Göring's father was a former governor-general of German Southwest-Africa. Both the notion of Germans needing more Lebensraum and the concept of dealing with troublesome minorities by "concentrating" them in camps and killing the economically unproductive ones to make this practice economically sustainable carry over fairly directly from the German colonial empire.
Couldn't really afford conflict with the British. We did name thousands of streets after Boer war heroes, though. And this did play a role in the run up to WWII. People with family there had a hard time accepting that Germans could be more evil than the British. After WWII everyone forgot about it.
Interesting fact: there are direct connections between a German that studied the British concentration camps in South Africa and administered German concentration camps in the Herero genocide, and the Nazis (source).