63cd4f5fdc
Incorporated patchset 1 review comments Updated patchset 5 review comments Updated patchset 6 review comments Fixed merge conflicts Updated patchset 8 review comments Change-Id: Icd7b08ab69273f6073b960a13cf59905532f851a Signed-off-by: Juanita-Balaraj <juanita.balaraj@windriver.com>
68 lines
2.3 KiB
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68 lines
2.3 KiB
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.. rhb1561120463240
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.. _kubernetes-user-tutorials-about-persistent-volume-support:
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===============================
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About Persistent Volume Support
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===============================
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Persistent Volume Claims \(PVCs\) are requests for storage resources in your
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cluster. By default, container images have an ephemeral file system. In order
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for containers to persist files beyond the lifetime of the container, a
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Persistent Volume Claim can be created to obtain a persistent volume which the
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container can mount and read/write files.
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Management and customization tasks for Kubernetes |PVCs|
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can be accomplished by using StorageClasses set up by two Helm charts;
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**rbd-provisioner** and **cephfs-provisioner**. The **rbd-provisioner**,
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and **cephfs-provisioner** Helm charts are included in the
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**platform-integ-apps** system application, which is automatically loaded and
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applied as part of the |prod| installation.
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PVCs are supported with the following options:
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- with accessMode of ReadWriteOnce backed by Ceph RBD
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- only one container can attach to these PVCs
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- management and customization tasks related to these PVCs are done
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through the **rbd-provisioner** Helm chart provided by
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platform-integ-apps
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- with accessMode of ReadWriteMany backed by CephFS
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- multiple containers can attach to these PVCs
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- management and customization tasks related to these PVCs are done
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through the **cephfs-provisioner** Helm chart provided by
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platform-integ-apps
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After platform-integ-apps is applied the following system configurations are
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created:
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- **Ceph Pools**
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.. code-block:: none
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~(keystone_admin)]$ ceph osd lspools
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kube-rbd
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kube-cephfs-data
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kube-cephfs-metadata
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- **CephFS**
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.. code-block:: none
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~(keystone_admin)]$ ceph fs ls
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name: kube-cephfs, metadata pool: kube-cephfs-metadata, data pools: [kube-cephfs-data ]
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- **Kubernetes StorageClasses**
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.. code-block:: none
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~(keystone_admin)]$ kubectl get sc
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NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION
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cephfs ceph.com/cephfs Delete Immediate false
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general (default) ceph.com/rbd Delete Immediate false
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