Configuring storage for the content services environment
Storage is required that is external to the containers in the content services environment. You set up or configure storage to prepare for the container configuration and deployment.
About this task
Each component container requires shared persistent storage to manage configuration information, application working space, and logs. Additionally, you can decide to set up file store areas to store document content and index areas to build full text indexes.
- For more information about persistent volumes, refer to the Kubernetes documentation for persistent volumes.
The storage classes and persistent volumes carry the details of the real storage, which is then made available for use by cluster users without having any knowledge of the underlying infrastructure. A cluster administrator defines and creates a persistent volume by providing the cloud infrastructure with the details of the implementation of the storage. That storage can be a number of different types including a cloud-provider-specific storage system.
- Dynamically provision storage through the operator functions
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The StorageClass resource object describes and classifies storage that can be requested, as well as provides a means for passing parameters for dynamically provisioned storage on demand. StorageClass objects can also serve as a management mechanism for controlling different levels of storage and access to the storage. Cluster administrators define and create the StorageClass objects that users can request without needing any intimate knowledge about the underlying storage volume sources.
The persistent volume framework provided by the cloud platform enables both these functionalities and allows administrators to provision a cluster with persistent storage.
For specifics related to the cloud platform you are deploying into, refer to the documentation given by the your cloud provider or cloud platform.
If dynamic provisioning is used, the deployment can optionally utilize three storage classes to meet the "slow", "medium", and "fast" storage for the Cloud Pak components. You provide the names of these storage classes using these parameters in the custom resource YAML file:sc_slow_file_storage_classname: sc_medium_file_storage_classname: sc_fast_file_storage_classname:
To avoid complexity, you can use the same storage class for "slow", "medium", and "fast". However to avoid potential performance issues, that single storage class should target fast storage.
- Combine manually created storage and dynamically provisioned storage
- Storage can be provisioned using a mixture of static and dynamic. The operator uses the
persistent volume claim names, of the default values, to determine if a claim already exists.
- If the claim does not exist, dynamic provisioning is used. The persistent volume claim names provided in the custom resource YAML are used when the claim is created.
- If the claim does exist, that claim is used when deploying.
- If static provisioning is used, the persistent volumes and persistent volume claims must be pre-created and the persistent volume claim name provided in the CR.
- Configuration information shared by all container instances, or replicas, for a particular component. This storage experiences minimal accesses or changes. For that reason, a low quality of service (QoS) type of disk is acceptable. The operator will provision a PVC from the sc_slow_file_storage_classname.
- Logs with a potentially high number of writes and dynamic disk space requirements, where system performance benefits from disk with a higher quality of service. The operator will provision a PVC from the sc_medium_file_storage_classname.
- Application working space for a particular component. This storage, under certain workloads, experiences high rates of access. System performance benefits from disk with a higher quality of service. The operator will provision a PVC from the sc_fast_file_storage_classname.
- Data where the disk subsystem must meet a set of requirements for I/Os per second, space, backup power supplies, and so on, and have a long life expectancy. These disk subsystems might also be configured to meet high availability and recoverability requirements as needed by the organization. The operator will provision a PVC from the sc_fast_file_storage_classname.
accessModes: - ReadWriteMany
persistentVolumeReclaimPolicy: Retain
When you prepare your environment, record the settings so that these values are available to enter into the custom resource YAML file for deployment and configuration. For lists of the parameters that you need to collect, see the following information: Content services parameters.