排空 Istio Pod 時，部分節點可能不會排空，因為它們的備用資源數量為 1，而系統需要 3 個備用資源或更多備用資源。為避免這種情況，您應將每個資源的副本數量下限設為至少 3。
備份及排空 Istio 節點時，您可能會看到類似以下的錯誤訊息：
kubectl drain` failed to evict and reschedule pods to another node due to PodDisruptionBudget definitions:
===
NAMESPACE NAME MIN AVAILABLE MAX UNAVAILABLE ALLOWED DISRUPTIONS AGE
istio-system istio-ingressgateway 1 N/A 2 5d11h
istio-system istio-pilot 1 N/A 2 5d11h
===
[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["難以理解","hardToUnderstand","thumb-down"],["資訊或程式碼範例有誤","incorrectInformationOrSampleCode","thumb-down"],["缺少我需要的資訊/範例","missingTheInformationSamplesINeed","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["上次更新時間：2025-07-10 (世界標準時間)。"],[[["This documentation applies specifically to Apigee hybrid users and does not have an equivalent for Apigee Edge."],["Draining Istio pods may fail if the replica count is less than 3, therefore a minimum of 3 replicas should be set."],["Errors during Istio node backup and draining can occur due to `PodDisruptionBudget` definitions."],["Setting the `istio.ingressgateway.replicaCountMin` and `istio.pilot.replicaCountMin` properties to 3 or higher can resolve issues for `istio-ingressgateway` and `istio-pilot`."],["For other Istio components without a `replicaCountMin` property, consult the GKE documentation or the Istio documentation for guidance."]]],[]]
