Harvester volume expansion: block device size vs guest file system capacity

Harvester utilizes Longhorn to provide distributed block storage for virtual machines, supporting online volume expansion to increase disk size without requiring a VM reboot.

While the Harvester UI and the underlying Longhorn engine can resize the block device, there is a technical gap between the block-level expansion and the guest operating system's recognition of that space. The Kubernetes PV/PVC layer updates the volume size, but the guest file system (such as ext4 or XFS) may not automatically expand to occupy the newly allocated capacity.

Given that shrinking volumes is unsupported and potentially destructive, it is necessary to define the expected automation boundary for this process.

• Does Harvester provide a mechanism to trigger the guest file system expansion automatically?
• Which guest OS distributions and file system types are natively supported for online resizing without manual intervention?