Use instance for volume names

variables.yml

@@ -255,9 +255,14 @@ pg:
 
   # Volumes
   volumes:
+    # The data volume is used to store postgres data
+    # It'll be opened as single-node-writer, and it's recommended to be a block based volume (eg, iSCSI)
+    # The volumes are connected using per_alloc, so the alloc ID will be appended. Eg postgres-data[0], postgres-data[1] etc.
     data:
       type: csi
-      source: postgres-data
+      source: '[[ .pg.instance ]]-data'
+    # Backup volume (can be used for pgbackrest and dumps)
+    # Will be opened as multi-node-multi-writer. Can be NFS
     backup:
       type: csi
-      source: postgres-backup
+      source: '[[ .pg.instance ]]-backup'