Persistent Storage in Containers Questions and Answers for Viva

Answer-1: Persistent storage allows data to be retained beyond the lifecycle of individual containers, enabling data durability and statefulness.

Answer-2: Containers are ephemeral by design; persistent storage is needed to store data that must survive container restarts or failures.

Answer-3: Common types include volumes, bind mounts, network-attached storage (NAS), and cloud storage services.

Answer-4: A Docker Volume is a storage mechanism that allows data to persist independently of container lifecycle.

Answer-5: Bind mounts link to files or directories on the host system directly, while volumes are managed by Docker and stored in Docker's storage area.

Answer-6: PersistentVolumes represent storage resources in a Kubernetes cluster abstracted from the underlying storage implementation.

Answer-7: A PVC is a request for storage by a user that binds to a PersistentVolume matching the request.

Answer-8: Storage is provisioned as PersistentVolumes by admins or dynamically via StorageClasses; users consume storage via PersistentVolumeClaims.

Answer-9: Dynamic provisioning automatically provisions storage volumes when a PVC is created, eliminating manual PV creation.

Answer-10: StorageClasses define different types of storage (e.g., SSD, HDD, cloud storage) and parameters for dynamic volume provisioning.

Answer-11: Yes, multiple containers can share storage using shared volumes or networked storage solutions.

Answer-12: ReadWriteOnce allows a volume to be mounted as read-write by a single node; ReadWriteMany allows multiple nodes to mount the volume simultaneously.

Answer-13: Cloud storage options include AWS EBS, Azure Disk Storage, Google Persistent Disk, and managed NFS services.

Answer-14: and how does it relate to persistent storage?

Answer-15: By using volumes or bind mounts which exist outside the container filesystem.

Answer-16: Ephemeral storage is temporary and deleted with the container; persistent storage remains intact beyond the container's lifecycle.

Answer-17: By snapshotting volumes, copying data to external backup systems, or exporting data using container-aware backup tools.

Answer-18: CSI is a standardized interface that allows third-party storage providers to integrate with Kubernetes.

Answer-19: Using the "volumes" section to declare volumes and mount them into containers.

Answer-20: Challenges include volume lifecycle management, data consistency, performance, and ensuring security.

Answer-21: NAS provides file-level access over the network; SAN provides block-level storage access over a network.

Answer-22: Containers can access S3, but object storage is usually accessed via APIs and not mounted as traditional file systems.

Answer-23: Persistent storage can reduce portability because data location and storage dependencies must be managed when moving containers.

Answer-24: By applying encryption, access controls, and securing storage endpoints and credentials.

Answer-25: and is it persistent?

Answer-26: Snapshots capture the state of a volume at a point in time, allowing backups and restoration.

Answer-27: It allows a volume to be mounted as read-only by multiple nodes simultaneously.

Answer-28: Check events, describe PVs and PVCs, inspect logs of storage provisioners, and validate volume attachment status.

Answer-29: hostPath mounts a directory from the node filesystem directly; PersistentVolumes abstract storage from underlying infrastructure.

Answer-30: Each Pod in a StatefulSet is associated with its own PersistentVolumeClaim ensuring stable storage.

Answer-31: Common drivers include local, aufs, overlay2, and third-party volume plugins.

Answer-32: By copying volume data to new storage backends or using storage migration tools.

Answer-33: It automates PVC creation for each Pod replica in a StatefulSet.

Answer-34: Volumes can be retained, deleted, or recycled based on the reclaim policy of the PersistentVolume.

Answer-35: It defines what happens to the physical storage when a PersistentVolumeClaim is deleted.

Answer-36: Local volumes use node disks; cloud persistent volumes use networked block or file storage.

Answer-37: By coordinating volume mounts, locking, and using storage systems supporting concurrent access.

Answer-38: FlexVolume is an older interface for integrating storage drivers before CSI became standard.

Answer-39: By writing data to the volume inside the container, restarting the container, and verifying data persistence.

Answer-40: Volume mounts are managed by Docker; bind mounts are direct host filesystem mounts.

Answer-41: Using StatefulSets with PVCs or using shared storage solutions supporting multiple mounts.

Answer-42: Use dynamic provisioning, separate data from app containers, secure data, and monitor storage health.

Answer-43: It defines driver-specific parameters for snapshot creation of PersistentVolumes.

Answer-44: Use cloud-agnostic storage solutions or synchronize data across providers.

Answer-45: Through cloud-specific CSI drivers that provision and manage volumes dynamically.

Answer-46: Volume plugins enable Kubernetes to work with different storage backends and types.

Answer-47: PVCs are created by users, bound to PVs by Kubernetes, used by Pods, and eventually deleted releasing the PV.

Answer-48: The PVC remains unbound until a matching PV becomes available or is dynamically provisioned.

Answer-49: They store database files and logs on persistent volumes to maintain data durability and recovery.

Answer-50: Tools like Prometheus, Grafana, and Kubernetes dashboard can be used to monitor storage metrics.