diff --git a/src/middlewared/middlewared/etc_files/scst.conf.mako b/src/middlewared/middlewared/etc_files/scst.conf.mako
index 8c905d33cd3f7..02fcdf9dd622b 100644
--- a/src/middlewared/middlewared/etc_files/scst.conf.mako
+++ b/src/middlewared/middlewared/etc_files/scst.conf.mako
@@ -137,6 +137,7 @@
     missing_extents = []
     extents_io = {'vdisk_fileio': [], 'vdisk_blockio': []}
     for extent in extents.values():
+        extent['name'] = extent['name'].replace('.', '_').replace('/', '-')  # CORE ctl device names are incompatible with SCALE SCST
         if extent['locked']:
             middleware.logger.debug(
                 'Skipping generation of extent %r as the underlying resource is locked', extent['name']
@@ -160,7 +161,6 @@
                 missing_extents.append(extent['id'])
                 continue
 
-        extent['name'] = extent['name'].replace('.', '_')  # CORE ctl device names are incompatible with SCALE SCST
         extents_io[extents_io_key].append(extent)
         all_extent_names.append(extent['name'])
 
diff --git a/src/middlewared/middlewared/plugins/iscsi_/global_linux.py b/src/middlewared/middlewared/plugins/iscsi_/global_linux.py
index f8d218324b619..4e889eed25e09 100644
--- a/src/middlewared/middlewared/plugins/iscsi_/global_linux.py
+++ b/src/middlewared/middlewared/plugins/iscsi_/global_linux.py
@@ -108,8 +108,8 @@ def resync_lun_size_for_zvol(self, id_):
 
         try:
             # CORE ctl device names are incompatible with SCALE SCST
-            # so (similarly to scst.mako.conf) replace period with underscore
-            extent_name = extent[0]["name"].replace('.', '_')
+            # so (similarly to scst.mako.conf) replace period with underscore, slash with dash
+            extent_name = extent[0]["name"].replace('.', '_').replace('/', '-')
             with open(f'/sys/kernel/scst_tgt/devices/{extent_name}/resync_size', 'w') as f:
                 f.write('1')
         except Exception as e: