Merge branch 'vg-exception-handling' into 'master'

Handle that one vg exception

See merge request !44

scripts/backstep-traceback-auto

@@ -104,7 +104,13 @@ for lv in ast.literal_eval(config.get(PERIOD, "backup_lvs")):
 
     bind_mount_args = []
     lvm_snapshot_args = []
-    VG = "lvm-raid"
+
+    if os.path.exists("/dev/lvm-raid/" + lv):
+        VG = "lvm-raid"
+    elif os.path.exists("/dev/lvm-cache/" + lv):
+        VG = "lvm-cache"
+    else:
+        continue
 
     if "," in lv:
         lv, bind_mount = lv.split(",")