diff --git a/kubernetes/apps/paperless/paperless.yaml b/kubernetes/apps/paperless/paperless.yaml
index 762d2e29..32de58cb 100644
--- a/kubernetes/apps/paperless/paperless.yaml
+++ b/kubernetes/apps/paperless/paperless.yaml
@@ -208,9 +208,25 @@ spec:
             seccompProfile:
               type: RuntimeDefault
       volumes:
+        # paperless-data-block (RWO, ceph-block), NOT paperless-data
+        # (RWX, ceph-filesystem). Only this Deployment ever mounted the volume,
+        # and its contents are single-writer state — the Whoosh index,
+        # classification model, celerybeat schedule, logs. Being on CephFS meant
+        # every access went through the MDS: 22 requests/sec sustained with zero
+        # CI running, ~15 journal events/sec against 2 directory commits per
+        # 180s, i.e. cap/inode churn rather than file writes. That was most of
+        # the constant 7-8 GB/day on cephfs-metadata, and that pool is size 3.
+        #
+        # `consume` and `media` below STAY on CephFS: the ftp-scanner writes to
+        # those from another node, so they genuinely need RWX.
+        #
+        # paperless-data is retained (prune: disabled) as the rollback. Do not
+        # delete it until search has been confirmed working — that is what
+        # proves the Whoosh index survived the copy, not merely that paperless
+        # starts. Migration record: MIGRATION-data-to-block.md.
         - name: data
           persistentVolumeClaim:
-            claimName: paperless-data
+            claimName: paperless-data-block
         - name: media
           persistentVolumeClaim:
             claimName: paperless-media