Enable RBD ReadWriteOnly Additional Storage Classes¶
Additional storage classes can be added to the default RBD provisioner service.
About this task
Some reasons for adding an additional storage class include:
managing Ceph resources for particular namespaces in a separate Ceph pool; simply for Ceph partitioning reasons
using an alternate Ceph Storage Tier, for example. with faster drives
A modification to the configuration (Helm overrides) of the RBD provisioner service is required to enable an additional storage class
The following example that illustrates adding a second storage class to be utilized by a specific namespace.
Note
Due to limitations with templating and merging of overrides, the entire storage class must be redefined in the override when updating specific values.
Procedure
List installed Helm chart overrides for the platform-integ-apps.
~(keystone_admin)]$ system helm-override-list platform-integ-apps +--------------------+----------------------+ | chart name | overrides namespaces | +--------------------+----------------------+ | ceph-pools-audit | ['kube-system'] | | cephfs-provisioner | ['kube-system'] | | rbd-provisioner | ['kube-system'] | +--------------------+----------------------+
Review existing overrides for the rbd-provisioner chart. You will refer to this information in the following step.
~(keystone_admin)$ system helm-override-show platform-integ-apps rbd-provisioner kube-system
Create an overrides yaml file defining the new namespaces.
In this example we will create the file
/home/sysadmin/update-storageclass.yamlwith the following content:~(keystone_admin)]$ cat <<EOF > ~/update-storageclass.yaml storageClasses: - additionalNamespaces: [default, kube-public, new-app, new-app2, new-app3] chunk_size: 64 crush_rule_name: storage_tier_ruleset name: general pool_name: kube-rbd replication: 1 userId: ceph-pool-kube-rbd userSecretName: ceph-pool-kube-rbd - additionalNamespaces: [ new-sc-app ] chunk_size: 64 crush_rule_name: storage_tier_ruleset name: special-storage-class pool_name: new-sc-app-pool replication: 1 userId: ceph-pool-new-sc-app userSecretName: ceph-pool-new-sc-app EOF
Apply the overrides file to the chart.
~(keystone_admin)]$ system helm-override-update --values /home/sysadmin/update-storageclass.yaml platform-integ-apps rbd-provisioner kube-system +----------------+-----------------------------------------+ | Property | Value | +----------------+-----------------------------------------+ | name | rbd-provisioner | | namespace | kube-system | | user_overrides | storageClasses: | | | - additionalNamespaces: | | | - default | | | - kube-public | | | - new-app | | | - new-app2 | | | - new-app3 | | | chunk_size: 64 | | | crush_rule_name: storage_tier_ruleset | | | name: general | | | pool_name: kube-rbd | | | replication: 1 | | | userId: ceph-pool-kube-rbd | | | userSecretName: ceph-pool-kube-rbd | | | - additionalNamespaces: | | | - new-sc-app | | | chunk_size: 64 | | | crush_rule_name: storage_tier_ruleset | | | name: special-storage-class | | | pool_name: new-sc-app-pool | | | replication: 1 | | | userId: ceph-pool-new-sc-app | | | userSecretName: ceph-pool-new-sc-app | +----------------+-----------------------------------------+
Confirm that the new overrides have been applied to the chart.
The following output has been edited for brevity.
~(keystone_admin)]$ system helm-override-show platform-integ-apps rbd-provisioner kube-system +--------------------+------------------------------------------------------+ | Property | Value | +--------------------+------------------------------------------------------+ | attributes | enabled: true | | | | | combined_overrides | ... | | | | | name | | | namespace | | | system_overrides | ... | | | | | user_overrides | storageClasses: | | | - additionalNamespaces: | | | - default | | | - kube-public | | | - new-app | | | - new-app2 | | | - new-app3 | | | chunk_size: 64 | | | crush_rule_name: storage_tier_ruleset | | | name: general | | | pool_name: kube-rbd | | | replication: 1 | | | userId: ceph-pool-kube-rbd | | | userSecretName: ceph-pool-kube-rbd | | | - additionalNamespaces: | | | - new-sc-app | | | chunk_size: 64 | | | crush_rule_name: storage_tier_ruleset | | | name: special-storage-class | | | pool_name: new-sc-app-pool | | | replication: 1 | | | userId: ceph-pool-new-sc-app | | | userSecretName: ceph-pool-new-sc-app | +--------------------+------------------------------------------------------+
Apply the overrides.
Run the application-apply command.
~(keystone_admin)]$ system application-apply platform-integ-apps +---------------+--------------------------------------+ | Property | Value | +---------------+--------------------------------------+ | active | True | | app_version | 1.0-62 | | created_at | 2022-12-14T04:14:08.878186+00:00 | | manifest_file | fluxcd-manifests | | manifest_name | platform-integ-apps-fluxcd-manifests | | name | platform-integ-apps | | progress | None | | status | applying | | updated_at | 2022-12-14T04:45:09.204231+00:00 | +---------------+--------------------------------------+
Monitor progress using the application-list command.
~(keystone_admin)]$ system application-list +--------------------------+---------+-------------------------------------------+------------------+----------+-----------+ | application | version | manifest name | manifest file | status | progress | +--------------------------+---------+-------------------------------------------+------------------+----------+-----------+ | platform-integ-apps | 1.0-62 | platform-integ-apps-fluxcd-manifests | fluxcd-manifests | applied | completed | +--------------------------+---------+-------------------------------------------+------------------+----------+-----------+
You can now create and mount persistent volumes from the new RBD provisioner’s special storage class from within the new-sc-app application-specific namespace.
