$ kubectl scale sts web --replicas=5
statefulset.apps/web scaled
$ kubectl get pod -w -l app=nginx
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 12m
web-1 1/1 Running 0 12m
web-2 0/1 Pending 0 0s
web-2 0/1 Pending 0 0s
web-2 0/1 ContainerCreating 0 0s
web-2 0/1 ContainerCreating 0 1s
web-2 1/1 Running 0 2s
web-3 0/1 Pending 0 0s
web-3 0/1 Pending 0 0s
web-3 0/1 ContainerCreating 0 0s
web-3 0/1 ContainerCreating 0 1s
web-3 1/1 Running 0 2s
web-4 0/1 Pending 0 0s
web-4 0/1 Pending 0 0s
web-4 0/1 ContainerCreating 0 0s
web-4 0/1 ContainerCreating 0 1s
web-4 1/1 Running 0 1s
$ kubectl patch sts web -p '{"spec":{"replicas":3}}'
statefulset.apps/web patched
kubectl get pod -w -l app=nginx
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 15m
web-1 1/1 Running 0 15m
web-2 1/1 Running 0 2m35s
web-3 1/1 Running 0 2m33s
web-4 1/1 Running 0 2m31s
web-4 1/1 Terminating 0 3m45s
web-4 1/1 Terminating 0 3m45s
web-4 0/1 Terminating 0 3m45s
web-4 0/1 Terminating 0 3m46s
web-4 0/1 Terminating 0 3m46s
web-4 0/1 Terminating 0 3m46s
web-3 1/1 Terminating 0 3m48s
web-3 1/1 Terminating 0 3m48s
web-3 0/1 Terminating 0 3m49s
web-3 0/1 Terminating 0 3m50s
web-3 0/1 Terminating 0 3m50s
web-3 0/1 Terminating 0 3m50s