add class sections
Matthew Wong
parent
d70418625e
commit
676a4f1577
|
|
@ -93,6 +93,8 @@ Each PV contains a spec and status, which is the specification and status of the
|
|||
kind: PersistentVolume
|
||||
metadata:
|
||||
name: pv0003
|
||||
annotations:
|
||||
volume.beta.kubernetes.io/storage-class: "slow"
|
||||
spec:
|
||||
capacity:
|
||||
storage: 5Gi
|
||||
|
|
@ -145,6 +147,16 @@ In the CLI, the access modes are abbreviated to:
|
|||
| RDB | x | x | - |
|
||||
| VsphereVolume | x | - | - |
|
||||
|
||||
### Class
|
||||
|
||||
A PV can have a class, which is specified by setting the
|
||||
"volume.beta.kubernetes.io/storage-class" annotation to the name of a
|
||||
`StorageClass`. A PV of a particular class can only be bound to PVCs requesting
|
||||
that class. A PV with no annotation or its class annotation set to `""` has no
|
||||
class and can only be bound to PVCs that request no particular class.
|
||||
|
||||
In the future after beta, the `volume.beta.kubernetes.io/storage-class`
|
||||
annotation will become an attribute.
|
||||
|
||||
### Recycling Policy
|
||||
|
||||
|
|
@ -176,6 +188,8 @@ kind: PersistentVolumeClaim
|
|||
apiVersion: v1
|
||||
metadata:
|
||||
name: myclaim
|
||||
annotations:
|
||||
volume.beta.kubernetes.io/storage-class: "slow"
|
||||
spec:
|
||||
accessModes:
|
||||
- ReadWriteOnce
|
||||
|
|
@ -206,6 +220,36 @@ Claims can specify a [label selector](/docs/user-guide/labels/#label-selectors)
|
|||
|
||||
All of the requirements, from both `matchLabels` and `matchExpressions` are ANDed together – they must all be satisfied in order to match.
|
||||
|
||||
### Class
|
||||
|
||||
A claim can request a particular class by specifying the name of a
|
||||
`StorageClass`using the annotation `volume.beta.kubernetes.io/storage-class`.
|
||||
Only PVs of the requested class, ones with the same annotation as the PVC, can
|
||||
be bound to the PVC.
|
||||
|
||||
PVCs don't necessarily have to request a class, they can omit the annotation or
|
||||
set it to `""`. The cluster treats PVCs that don't request a class differently
|
||||
depending on whether the
|
||||
[`SimpleDefaultStorageClassForPVC` admission controller](docs/admin/admission-controllers/#simpledefaultstorageclassforpvc)
|
||||
is turned on.
|
||||
|
||||
* If the admission controller is turned on, the administrator may specify a
|
||||
default `StorageClass`. All PVCs that don't request a `StorageClass` can be
|
||||
bound only to PVs of that default. This means that the PVs those PVCs would
|
||||
normally be bound to, the PVs that have no class (no annotation or annotation
|
||||
equal to `""`), cannot be bound to any PVC. Specifying a default `StorageClass`
|
||||
is done by setting the annotation
|
||||
`storageclass.beta.kubernetes.io/is-default-class` equal to "true" in a
|
||||
`StorageClass` object. If the administrator does not specify a default, the
|
||||
cluster will respond to PVC creation as if the admission controller were turned
|
||||
off. If more than one default is specified, the admission controller will forbid
|
||||
the creation of all PVCs.
|
||||
* If the admission controller is turned off, the claim may be bound to volumes
|
||||
that have no class
|
||||
|
||||
In the future after beta, the `volume.beta.kubernetes.io/storage-class`
|
||||
annotation will become an attribute.
|
||||
|
||||
## Claims As Volumes
|
||||
|
||||
Pods access storage by using the claim as a volume. Claims must exist in the same namespace as the pod using the claim. The cluster finds the claim in the pod's namespace and uses it to get the `PersistentVolume` backing the claim. The volume is then mounted to the host and into the pod.
|
||||
|
|
@ -244,21 +288,10 @@ of a class, all of which are opaque to users, when first creating
|
|||
`StorageClass` objects, and the objects cannot be updated once they are
|
||||
created.
|
||||
|
||||
Users don't necessarily have to request a `StorageClass` in their PVC. The
|
||||
cluster treats PVCs that don't request a `StorageClass` differently depending
|
||||
on whether the
|
||||
[`SimpleDefaultStorageClassForPVC` admission controller](docs/admin/admission-controllers/#simpledefaultstorageclassforpvc) is turned on.
|
||||
* If the admission controller is turned on, the administrator may specify a
|
||||
default `StorageClass`. All PVCs that don't request a `StorageClass` will be
|
||||
bound only to PVs of that default. Specifying a default `StorageClass` is done
|
||||
by setting the annotation `storageclass.beta.kubernetes.io/is-default-class`
|
||||
equal to "true" in a `StorageClass` object. If the administrator does not
|
||||
specify a default, the cluster will respond to PVC creation as if the admission
|
||||
controller were turned off. If more than one default is specified, the
|
||||
admission controller will forbid the creation of all PVCs.
|
||||
* If the admission controller is turned off, the claim may be bound to any
|
||||
volume that does not belong to a `StorageClass` or that has a blank `""` value
|
||||
for its `volume.beta.kubernetes.io/storage-class` annotation.
|
||||
Administrators can specify a default `StorageClass` just for PVCs that don't
|
||||
request any particular class to bind to: see the
|
||||
[`PersistentVolumeClaim` section](docs/user-guide/persistent-volumes/index/#class-1)
|
||||
for details.
|
||||
|
||||
```yaml
|
||||
kind: StorageClass
|
||||
|
|
@ -297,8 +330,8 @@ parameters:
|
|||
```
|
||||
|
||||
* `type`: `io1`, `gp2`, `sc1`, `st1`. See AWS docs for details. Default: `gp2`.
|
||||
* `zone`: AWS zone. If not specified, a random zone in the same region as
|
||||
controller-manager will be chosen.
|
||||
* `zone`: AWS zone. If not specified, a random zone where the cluster has a node
|
||||
is chosen
|
||||
* `iopsPerGB`: only for `io1` volumes. I/O operations per second per GiB. AWS
|
||||
volume plugin multiplies this with size of requested volume to compute IOPS of
|
||||
the volume and caps it at 20 000 IOPS (maximum supported by AWS, see AWS docs).
|
||||
|
|
@ -319,34 +352,3 @@ provisionerParameters:
|
|||
* `type`: `pd-standard` or `pd-ssd`. Default: `pd-ssd`
|
||||
* `zone`: GCE zone. If not specified, a random zone in the same region as
|
||||
controller-manager will be chosen.
|
||||
|
||||
## Requesting a StorageClass
|
||||
|
||||
Users request a particular `StorageClass`, i.e. a `PersistentVolume` that
|
||||
belongs to and has the characteristics described by the `StorageClass`, by
|
||||
specifying the name of the class in their `PersistentVolumeClaim` using the
|
||||
annotation `volume.beta.kubernetes.io/storage-class`. Only a PV of the
|
||||
requested class, one with the same annotation as the PVC, can then be bound to
|
||||
the PVC.
|
||||
|
||||
```yaml
|
||||
kind: PersistentVolumeClaim
|
||||
apiVersion: v1
|
||||
metadata:
|
||||
name: myclaim
|
||||
annotations:
|
||||
"volume.beta.kubernetes.io/storage-class": "slow"
|
||||
spec:
|
||||
accessModes:
|
||||
- ReadWriteOnce
|
||||
resources:
|
||||
requests:
|
||||
storage: 10Gi
|
||||
```
|
||||
|
||||
If a PV of the requested class is not found, a new one will be provisioned
|
||||
using the `StorageClass`.
|
||||
|
||||
When a PVC specifies a `LabelSelector` in addition to requesting a
|
||||
`StorageClass`, the requirements are ANDed together: only a PV of the requested
|
||||
class and with the requested labels may be bound to the PVC.
|
||||
|
|
|
|||
Loading…
Reference in New Issue