Storage Layer

Scope

The storage layer covers persistent volumes, CSI drivers, storage classes, snapshots, object storage, backup tooling, and restore dependencies.

Components that belong here

• longhorn for block storage and snapshots
• csi-driver-nfs, democratic-csi, and nfs-subdir-external-provisioner for shared storage and dynamic provisioning
• minio for object storage where used as an application or backup dependency
• velero for backup and restore orchestration

Mandatory topics

• What storage classes exist and which workloads depend on them
• Which workloads are stateful and what their backup method is
• What snapshot or backup schedule exists and where restore artifacts live
• What the restore order is after data loss or cluster rebuild
• Capacity, retention, and replication assumptions

Required artifacts

• Storage class catalogue
• Stateful workload to backup-method mapping
• Snapshot and restore workflow summary
• Cluster rebuild dependency order for stateful services
• Capacity and retention ownership notes

Recovery focus

This layer is the primary reference during:

• PVC attach or mount failures
• Storage class migrations
• Snapshot restores
• Full-cluster rebuilds where state must survive infrastructure loss