diff --git a/tests/test_check.py b/tests/test_check.py
index 9689fda..0fec153 100644
--- a/tests/test_check.py
+++ b/tests/test_check.py
@@ -107,21 +107,44 @@ dir/testfile	0	2e863f1fcccd6642e4e28453eba10d2d3f74d798
 """, buf.getvalue())
 
 
-    def test_brokenpipe_cleanup_filesystem(self):
-        """test if stuff is cleaned up correctly, in debugging mode , when a pipe breaks. """
+    # def test_brokenpipe_cleanup_filesystem(self):
+    #     """test if stuff is cleaned up correctly, in debugging mode , when a pipe breaks. """
+    #
+    #     prepare_zpools()
+    #     shelltest("cp tests/data/whole /test_source1/testfile")
+    #     shelltest("zfs snapshot test_source1@test")
+    #
+    #     #breaks pipe when grep exists:
+    #     #important to use --debug, since that generates extra output which would be problematic if we didnt do correct SIGPIPE handling
+    #     shelltest("python -m zfs_autobackup.ZfsCheck test_source1@test --debug | grep -m1 'Hashing tree'")
+    #
+    #     #should NOT be mounted anymore if cleanup went ok:
+    #     self.assertNotRegex(shelltest("mount"), "test_source1@test")
+
+    def test_brokenpipe_cleanup_volume(self):
 
         prepare_zpools()
-        shelltest("cp tests/data/whole /test_source1/testfile")
-        shelltest("zfs snapshot test_source1@test")
+        shelltest("zfs create -V200M test_source1/vol")
+        shelltest("zfs snapshot test_source1/vol@test")
 
         #breaks pipe when grep exists:
         #important to use --debug, since that generates extra output which would be problematic if we didnt do correct SIGPIPE handling
-        shelltest("python -m zfs_autobackup.ZfsCheck test_source1@test --debug | grep -m1 Hashing")
-
-        #should NOT be mounted anymore if cleanup went ok:
-        self.assertNotRegex(shelltest("mount"), "test_source1@test")
-
+        shelltest("python -m zfs_autobackup.ZfsCheck test_source1/vol@test --debug | grep -m1 'Hashing dev'")
 
+        r = shelltest("zfs list -H -o name -r -t all " + TEST_POOLS)
+        self.assertMultiLineEqual(r, """
+test_source1
+test_source1/fs1
+test_source1/fs1/sub
+test_source1/vol
+test_source1/vol@test
+test_source2
+test_source2/fs2
+test_source2/fs2/sub
+test_source2/fs3
+test_source2/fs3/sub
+test_target1
+""")
 
 
 
diff --git a/zfs_autobackup/ZfsCheck.py b/zfs_autobackup/ZfsCheck.py
index 2e2828e..4cb9f7e 100644
--- a/zfs_autobackup/ZfsCheck.py
+++ b/zfs_autobackup/ZfsCheck.py
@@ -31,6 +31,9 @@ class ZfsCheck(CliBase):
         group.add_argument('--count', metavar="COUNT", default=int((100 * (1024 ** 2)) / 4096),
                            help="Generate a hash for every COUNT blocks. default %(default)s", type=int)  # 100MiB
 
+        group.add_argument('--check', '-c', metavar="FILE", default=None,
+                           help="Read hashes from FILE and check them")
+
         return parser
 
     def parse_args(self, argv):
@@ -153,25 +156,5 @@ def cli():
 
 
 if __name__ == "__main__":
-    # try:
-    #     while True:
-    #         # print("stderr", file=sys.stderr)
-    #         print("loop")
-    #         sys.stdout.flush()
-    #
-    # except BrokenPipeError:
-    #     output_redir()
-    #     print("pipe brookn", file=sys.stderr)
-    #     sys.stderr.flush()
-    #
-    #     devnull = os.open(os.devnull, os.O_WRONLY)
-    #     os.dup2(devnull, sys.stdout.fileno())
-    #
-    #     print("stout")
-    #     sys.stdout.flush()
-    #
-    #
-    #     print("hier kom ik nie", file=sys.stderr)
-    #     open("yo" ,"w")
 
     cli()