RHOCP 4 でサイズ 1x.demo の LokiStack を実行しているときにノードを drain できない

Issue

• LokiStack をサイズ 1x.demo で実行している場合、Loki Pod を実行しているノードは pod's disruption budget エラーにより drain できません。

  E0208 09:40:06.497414       1 drain_controller.go:142] error when evicting pods/"logging-loki-distributor-84f4ccd8d5-5xz6m" -n "openshift-logging" (will retry after 5s): Cannot evict pod as it would violate the pod's disruption budget.
  E0208 09:40:07.709796       1 drain_controller.go:142] error when evicting pods/"logging-loki-index-gateway-0" -n "openshift-logging" (will retry after 5s): Cannot evict pod as it would violate the pod's disruption budget.
  E0208 09:40:09.291697       1 drain_controller.go:142] error when evicting pods/"logging-loki-ingester-0" -n "openshift-logging" (will retry after 5s): Cannot evict pod as it would violate the pod's disruption budget.