From 5bc7de4f1d14dcc530172998b55a349950af8408 Mon Sep 17 00:00:00 2001 From: Peter Novotnak Date: Tue, 16 Aug 2016 09:14:22 -0700 Subject: [PATCH] noted exclusivity of volume claims and namespacing --- docs/user-guide/persistent-volumes/index.md | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/docs/user-guide/persistent-volumes/index.md b/docs/user-guide/persistent-volumes/index.md index e4ef046107..fdfba107e8 100644 --- a/docs/user-guide/persistent-volumes/index.md +++ b/docs/user-guide/persistent-volumes/index.md @@ -33,7 +33,7 @@ A cluster administrator will create a number of PVs. They carry the details of t ### Binding -A user creates a `PersistentVolumeClaim` with a specific amount of storage requested and with certain access modes. A control loop in the master watches for new PVCs, finds a matching PV (if possible), and binds them together. The user will always get at least what they asked for, but the volume may be in excess of what was requested. +A user creates a `PersistentVolumeClaim` with a specific amount of storage requested and with certain access modes. A control loop in the master watches for new PVCs, finds a matching PV (if possible), and binds them together. The user will always get at least what they asked for, but the volume may be in excess of what was requested. Once bound, `PersistentVolumeClaim` binds are exclusive, regardless of the mode used to bind them. Claims will remain unbound indefinitely if a matching volume does not exist. Claims will be bound as matching volumes become available. For example, a cluster provisioned with many 50Gi PVs would not match a PVC requesting 100Gi. The PVC can be bound when a 100Gi PV is added to the cluster. @@ -212,3 +212,7 @@ spec: persistentVolumeClaim: claimName: myclaim ``` + +### A Note on Namespaces + +`PersistentVolumes` binds are exclusive, and since `PersistentVolumeClaims` are namespaced objects, mounting claims with "Many" modes (`ROX`, `RWX`) is only possible within one namespace.