Conquered Race revolting

[Octavian30 (OP)]

How do I stop a conquered race from getting ever higher unrest levels? Apart from ever greater numbers of occupation forces?

[Sotak246]

Lots of Garrison troops are about it, unless you want to go into SM mode and manually remove the unrest points that accumulate.

[UnLimiTeD]

Move them into cryoholds, drop them in a radioactive wasteland, problem solved.

[Hawkeye]

What Sotak246 said.
Also note: The supression value is the same as the defensive combat power of the troops used. Therefore, raising the initial ground combat tech, which is rather cheap in terms of research points, can greately increasing the garrison value of your troops. In addition, build divisional and brigade HQs and put commanders with good ground combat ratings in (same goes for the batallions, of course).
All boni stack, i.e. a Garrison Battalion with a +10% commander, in a brigade with a +15% commander, in a division with a +20% commander gets a 45% boost to its combat power and therfore also to its garrison value.

[Steve Walmsley]

How do I stop a conquered race from getting ever higher unrest levels? Apart from ever greater numbers of occupation forces?

On the Ground Units tab for that population, there will be a required occupation strength. That is the total defence strength required for the occupation. There will be unrest if the defence strength falls below that number. Building cheap garrison troops is a fast way to increase your defence strength. As others have noted, increasing your Ground Unit Strength through research and organising your units into brigades and divisions with good commanders can also raise that strength considerably.

Steve