UCARP: prevent the original master from taking over the VIP when it comes back after failure?

Solution 1:

For UCARP, I think the trick is to start it in "neutral" mode using the --neutral flag, so that it doesn't automatically assume the master role or try anything upon start. Looking at one of my setups, here's the full command line. Perhaps --neutral applies because we have upscripts and downscripts applied at startup and shutdown, but it's worth a try.

/path/to/ucarp0 -v 42 -p kitteh0 --interface=bond0 -a 192.168.100.250 -s 192.168.100.172 -b 5 -r 3 --upscript=/path/to/ucarp/upscript0 --downscript=/path/to/ucarp/downscript0 --neutral -z -B

Solution 2:

I don't see the ucarp clusters (which i inherited) ever switching back by themselves.

They are indeed set to preempt=no.