Persistent volume is not a supported volume type for snapshots (Velero, MinIO, FSB)

We need to backup PV on an on-premise Kubernetes cluster, so we installed Velero, linked to MinIO, with Velero's File System Backup. No PV are backed up and no error is shown, only this mention appears in the logs "Persistent volume is not a supported volume type for snapshots, skipping". Does someone have a clue to be able to backup PV on an on-premise cluster without having to use external Cloud providers ?

Details

Velero was installed using the following command (credentials-minio containing the MinIO's bucket access keys):

velero install \
    --provider aws \
    --plugins velero/velero-plugin-for-aws:v1.2.1 \
    --bucket ka-backup \
    --secret-file ./credentials-minio \
    --use-node-agent \
    --backup-location-config region=minio,s3ForcePathStyle="true",s3Url=http://minio-1679064025.minio.svc:9000 \
    --snapshot-location-config region=minio

The result of a backup of namespaces shows no error, nor warnings as seen below and the status of the phase is completed.

velero backup describe acme -n velero --kubeconfig ../VKATEST.config
Name:         acme
Namespace:    velero
Labels:       velero.io/storage-location=default
Annotations:  velero.io/source-cluster-k8s-gitversion=v1.25.6
              velero.io/source-cluster-k8s-major-version=1
              velero.io/source-cluster-k8s-minor-version=25

Phase:  Completed

Errors:    0
Warnings:  0

Namespaces:
  Included:  acme
  Excluded:  <none>

Resources:
  Included:        *
  Excluded:        <none>
  Cluster-scoped:  auto

Label selector:  <none>

Storage Location:  default

Velero-Native Snapshot PVs:  auto

TTL:  720h0m0s

CSISnapshotTimeout:  10m0s

Hooks:  <none>

Backup Format Version:  1.1.0

Started:    2023-03-20 14:40:18 +0100 CET
Completed:  2023-03-20 14:40:29 +0100 CET

Expiration:  2023-04-19 15:40:18 +0200 CEST

Total items to be backed up:  437
Items backed up:              437

Velero-Native Snapshots: <none included>

In the logs we can read at the end of the following extract, that: "Persistent volume is not a supported volume type for snapshots, skipping".

level=info msg="Backing up item" backup=velero/acme logSource="pkg/backup/item_backupper.go:132" name=cassandra-logs-local-storage-fra-vkatest-ml5 namespace= resource=persistentvolumes
level=info msg="Executing takePVSnapshot" backup=velero/acme logSource="pkg/backup/item_backupper.go:412" name=cassandra-logs-local-storage-fra-vkatest-ml5 namespace= resource=persistentvolumes
level=info msg="label \"topology.kubernetes.io/zone\" is not present on PersistentVolume, checking deprecated label..." backup=velero/acme logSource="pkg/backup/item_backupper.go:445" name=cassandra-logs-local-storage-fra-vkatest-ml5 namespace= persistentVolume=cassandra-logs-local-storage-fra-vkatest-ml5 resource=persistentvolumes
level=info msg="label \"failure-domain.beta.kubernetes.io/zone\" is not present on PersistentVolume" backup=velero/acme logSource="pkg/backup/item_backupper.go:449" name=cassandra-logs-local-storage-fra-vkatest-ml5 namespace= persistentVolume=cassandra-logs-local-storage-fra-vkatest-ml5 resource=persistentvolumes
level=info msg="zone info not available in nodeAffinity requirements" backup=velero/acme logSource="pkg/backup/item_backupper.go:454" name=cassandra-logs-local-storage-fra-vkatest-ml5 namespace= persistentVolume=cassandra-logs-local-storage-fra-vkatest-ml5 resource=persistentvolumes
level=info msg="No volume ID returned by volume snapshotter for persistent volume" backup=velero/acme logSource="pkg/backup/item_backupper.go:478" name=cassandra-logs-local-storage-fra-vkatest-ml5 namespace= persistentVolume=cassandra-logs-local-storage-fra-vkatest-ml5 resource=persistentvolumes volumeSnapshotLocation=default
level=info msg="Persistent volume is not a supported volume type for snapshots, skipping." backup=velero/acme logSource="pkg/backup/item_backupper.go:489" name=cassandra-logs-local-storage-fra-vkatest-ml5 namespace= persistentVolume=cassandra-logs-local-storage-fra-vkatest-ml5 resource=persistentvolumes

Please let us know if you have a clue to be able to backup PV on an on-premise cluster without having to use external Cloud providers.

have you add option --default-volumes-to-restic(for older versions like 1.7) or --default-volumes-to-fs-backup(new versions) when doing velero backup?
could be same problem like: https://stackoverflow.com/questions/75803242/velero-volume-snapshots-contain-no-data-when-restoring-a-backup