azure availability set second VM shuts down first VM

Question

I've got two Ubuntu VMs in one availability set. When I start the second VM it takes a few minutes and the first VM stops.

Answer 1

An availability set is basically your way to get an SLA on uptime.

It is meant for when Microsoft has to patch/fix the VM host machines, in order to avoid that they take down your VM, they fire up the other VM in the availability set and then route all traffic to that instead.

Also, if something happens to the host machine of your ubuntu instance, all traffic is routed to your other one.

So, what you are observing is expected behavior.