diff --git a/core/src/test/java/org/dcache/nfs/v4/nlm/NlmLockTest.java b/core/src/test/java/org/dcache/nfs/v4/nlm/NlmLockTest.java
index 46492865c..eb26fc4c4 100644
--- a/core/src/test/java/org/dcache/nfs/v4/nlm/NlmLockTest.java
+++ b/core/src/test/java/org/dcache/nfs/v4/nlm/NlmLockTest.java
@@ -106,4 +106,49 @@ public void shouldAllowEndingLockRange() {
         assertFalse("false conflicting lock range", lock.isOverlappingRange(lock1));
         assertFalse("false conflicting lock range", lock.isOverlappingRange(lock2));
     }
+
+    @Test
+    public void shouldEqual() {
+        NlmLock lock1 = new NlmLock(lo1, nfs_lock_type4.WRITE_LT, 0, 1);
+        NlmLock lock2 = new NlmLock(lo1, nfs_lock_type4.WRITE_LT, 0, 1);
+
+        assertTrue("the same lock should be equal", lock1.equals(lock2));
+        assertTrue("equal objects must have the same hashcode", lock1.hashCode() == lock2.hashCode());
+    }
+
+    @Test
+    public void shouldNotBeEqualByOwner() {
+
+        NlmLock lock1 = new NlmLock(lo1, nfs_lock_type4.WRITE_LT, 0, nfs4_prot.NFS4_UINT64_MAX);
+        NlmLock lock2 = new NlmLock(lo2, nfs_lock_type4.WRITE_LT, 0, nfs4_prot.NFS4_UINT64_MAX);
+
+        assertFalse("lock with different owner can't be equal", lock1.equals(lock2));
+    }
+
+    @Test
+    public void shouldNotBeEqualByOffset() {
+
+        NlmLock lock1 = new NlmLock(lo1, nfs_lock_type4.WRITE_LT, 0, nfs4_prot.NFS4_UINT64_MAX);
+        NlmLock lock2 = new NlmLock(lo1, nfs_lock_type4.WRITE_LT, 1, nfs4_prot.NFS4_UINT64_MAX);
+
+        assertFalse("lock with different offsets can't be equal", lock1.equals(lock2));
+    }
+
+    @Test
+    public void shouldNotBeEqualByType() {
+
+        NlmLock lock1 = new NlmLock(lo1, nfs_lock_type4.WRITE_LT, 0, nfs4_prot.NFS4_UINT64_MAX);
+        NlmLock lock2 = new NlmLock(lo1, nfs_lock_type4.READ_LT, 0, nfs4_prot.NFS4_UINT64_MAX);
+
+        assertFalse("lock with different types can't be equal", lock1.equals(lock2));
+    }
+
+    @Test
+    public void shouldNotBeEqualByLegth() {
+
+        NlmLock lock1 = new NlmLock(lo1, nfs_lock_type4.WRITE_LT, 0, 1);
+        NlmLock lock2 = new NlmLock(lo1, nfs_lock_type4.WRITE_LT, 0, 2);
+
+        assertFalse("lock with different length can't be equal", lock1.equals(lock2));
+    }
 }
diff --git a/core/src/test/java/org/dcache/nfs/v4/nlm/SimpleLmTest.java b/core/src/test/java/org/dcache/nfs/v4/nlm/SimpleLmTest.java
index 1832745cb..9f4c9ef0d 100644
--- a/core/src/test/java/org/dcache/nfs/v4/nlm/SimpleLmTest.java
+++ b/core/src/test/java/org/dcache/nfs/v4/nlm/SimpleLmTest.java
@@ -292,6 +292,33 @@ public void testSplitLock() throws LockException {
         nlm.test(file1, lock3);
     }
 
+    @Test
+    public void testSplitWholeFileLock() throws LockException {
+        NlmLock lock1 = new LockBuilder()
+                .withOwner("owner1")
+                .from(0)
+                .length(nfs4_prot.NFS4_UINT64_MAX)
+                .forWrite()
+                .build();
+        nlm.lock(file1, lock1);
+
+        NlmLock lock2 = new LockBuilder()
+                .withOwner("owner1")
+                .from(1)
+                .length(nfs4_prot.NFS4_UINT64_MAX)
+                .forRead()
+                .build();
+        nlm.unlock(file1, lock2);
+
+        NlmLock lock3 = new LockBuilder()
+                .withOwner("owner2")
+                .from(1)
+                .length(1)
+                .forWrite()
+                .build();
+        nlm.test(file1, lock3);
+    }
+
     @Test(expected = LockDeniedException.class)
     public void testMergeOfOverlapingLocks() throws LockException {
         NlmLock lock1 = new LockBuilder()
@@ -319,6 +346,93 @@ public void testMergeOfOverlapingLocks() throws LockException {
         nlm.test(file1, lock3);
     }
 
+    @Test(expected = LockDeniedException.class)
+    public void testMergeOfContinuesLocks() throws LockException {
+        NlmLock lock1 = new LockBuilder()
+                .withOwner("owner1")
+                .from(74)
+                .length(nfs4_prot.NFS4_UINT64_MAX)
+                .forWrite()
+                .build();
+        nlm.lock(file1, lock1);
+
+        NlmLock lock2 = new LockBuilder()
+                .withOwner("owner1")
+                .from(0)
+                .length(75)
+                .forWrite()
+                .build();
+        nlm.lock(file1, lock2);
+
+        NlmLock lock3 = new LockBuilder()
+                .withOwner("owner2")
+                .from(1)
+                .length(100)
+                .forWrite()
+                .build();
+        nlm.test(file1, lock3);
+    }
+
+    @Test(expected = LockDeniedException.class)
+    public void testMergeOfWholeFileLocks() throws LockException {
+        NlmLock lock1 = new LockBuilder()
+                .withOwner("owner1")
+                .from(0)
+                .length(nfs4_prot.NFS4_UINT64_MAX)
+                .forWrite()
+                .build();
+        nlm.lock(file1, lock1);
+
+        NlmLock lock2 = new LockBuilder()
+                .withOwner("owner1")
+                .from(0)
+                .length(nfs4_prot.NFS4_UINT64_MAX)
+                .forWrite()
+                .build();
+        nlm.lock(file1, lock2);
+
+        NlmLock lock3 = new LockBuilder()
+                .withOwner("owner2")
+                .from(1)
+                .length(100)
+                .forWrite()
+                .build();
+        nlm.test(file1, lock3);
+    }
+
+    @Test
+    public void testLocAfterUnlockIfExist() throws LockException {
+        NlmLock lock1 = new LockBuilder()
+                .withOwner("owner1")
+                .from(0)
+                .length(1)
+                .forRead()
+                .build();
+        nlm.lock(file1, lock1);
+
+        nlm.unlockIfExists(file1, lock1);
+
+        NlmLock lock2 = new LockBuilder()
+                .withOwner("owner2")
+                .from(0)
+                .length(1)
+                .forWrite()
+                .build();
+        nlm.test(file1, lock2);
+    }
+
+    @Test
+    public void testUnlockIfExistNonExisting() throws LockException {
+        NlmLock lock1 = new LockBuilder()
+                .withOwner("owner1")
+                .from(0)
+                .length(1)
+                .forRead()
+                .build();
+
+        nlm.unlockIfExists(file1, lock1);
+    }
+
     public static class LockBuilder {
 
         private long offset;