Understanding Volume Mounts
Summary
Kubernetes and container runtimes such as Docker and Podman use volume mounts to persist stateful data across container or pod re-deployments. DH2i stores its configuration data in the /etc/dh2i directory, so this directory must be mounted to persistent storage to preserve cluster or gateway configuration.
Information
DH2i software is stateful because it needs to store its configuration information, and this information is required so the container can rejoin a cluster or gateway group after it restarts. The /etc/dh2i folder is where DH2i stores configuration info for DxOdyssey and DxEnterprise. Whether running in Kubernetes, Docker, or some other container platform, this folder should always be mounted into a volume. More information about how these platforms handle stateful data is included in the additional information section below.
DH2i software is stateful because it maintains configuration data that is required for a node or gateway to rejoin a cluster or gateway group after a restart. This configuration data is stored in the /etc/dh2i directory.
Regardless of the container platform or runtime in use - Kubernetes, Docker, Podman, or another OCI-compatible runtime - the /etc/dh2i directory should always be mounted to persistent storage.
- In Docker and Podman, this is typically accomplished using a named volume or bind mount.
- In Kubernetes, persistent storage is provided through PersistentVolumes (PVs) and PersistentVolumeClaims (PVCs).
Without a persistent volume mount for /etc/dh2i, container restarts or re-deployments will result in loss of DH2i configuration data, requiring the node or gateway to be reconfigured and rejoined to the cluster or gateway group.
For Kubernetes deployments, note that volumes and persistent volumes are distinct concepts. PersistentVolumes are required for DxEnterprise or DxOdyssey configuration data to persist between pod re-deployments.