--- assignees: - derekwaynecarr - janetkuo title: Limiting Storage Consumption --- This example demonstrates an easy way to limit the amount of storage consumed in a namespace. The following resources are used in the demonstration: * [Resource Quota](/docs/admin/resourcequota/) * [Limit Range](/docs/admin/limitrange/) * [Persistent Volume Claim](/docs/user-guide/persistent-volumes/) This example assumes you have a functional Kubernetes setup. ## Limiting Storage Consumption The cluster-admin is operating a cluster on behalf of a user population and the admin wants to control how much storage a single namespace can consume in order to control cost. The admin would like to limit: 1. The number of persistent volume claims in a namespace 2. The amount of storage each claim can request 3. The amount of cumulative storage the namespace can have ## LimitRange to limit requests for storage Adding a `LimitRange` to a namespace enforces storage request sizes to a minimum and maximum. Storage is requested via `PersistentVolumeClaim`. The admission controller that enforces limit ranges will reject any PVC that is above or below the values set by the admin. In this example, a PVC requesting 10Gi of storage would be rejected because it exceeds the 2Gi max. ``` apiVersion: v1 kind: LimitRange metadata: name: storagelimits spec: limits: - type: PersistentVolumeClaim max: storage: 2Gi min: storage: 1Gi ``` Minimum storage requests are used when the underlying storage provider requires certain minimums. For example, AWS EBS volumes have a 1Gi minimum requirement. ## StorageQuota to limit PVC count and cumulative storage capacity Admins can limit the number of PVCs in a namespace as well as the cumulative capacity of those PVCs. New PVCs that exceed either maximum value will be rejected. In this example, a 6th PVC in the namespace would be rejected because it exceeds the maximum count of 5. Alternatively, a 5Gi maximum quota when combined with the 2Gi max limit above, cannot have 3 PVCs where each has 2Gi. That would be 6Gi requested for a namespace capped at 5Gi. ``` apiVersion: v1 kind: ResourceQuota metadata: name: storagequota spec: hard: persistentvolumeclaims: "5" requests.storage: "5Gi" ``` ## Summary A limit range can put a ceiling on how much storage is requested while a resource quota can effectively cap the storage consumed by a namespace through claim counts and cumulative storage capacity. The allows a cluster-admin to plan their cluster's storage budget without risk of any one project going over their allotment.