The node was low on resource: ephemeral-storage. Container ex-aao-container was using 57485372Ki, which exceeds its request of 0. 

This doesn't mean that node literally has 0 storage available, its got about 80gb of ephemeral storage on my cluster, however this 80g is all the space available on pod's node - which means that this warning might become a problem on clusters with lots of pods sharing the same node.