diff --git a/src/blobstore/implementations/onblocks/impl/DataNodeView.h b/src/blobstore/implementations/onblocks/impl/DataNodeView.h
index ceeb81e8..48b03ae5 100644
--- a/src/blobstore/implementations/onblocks/impl/DataNodeView.h
+++ b/src/blobstore/implementations/onblocks/impl/DataNodeView.h
@@ -8,13 +8,16 @@
 #include "fspp/utils/macros.h"
 
 #include <memory>
+#include <cassert>
 
 namespace blobstore {
 namespace onblocks {
 
 class DataNodeView {
 public:
-  DataNodeView(std::unique_ptr<blockstore::Block> block): _block(std::move(block)) {}
+  DataNodeView(std::unique_ptr<blockstore::Block> block): _block(std::move(block)) {
+    assert(_block->size() == BLOCKSIZE_BYTES);
+  }
   virtual ~DataNodeView() {}
 
   DataNodeView(DataNodeView &&rhs) = default;
@@ -73,18 +76,16 @@ public:
     return const_cast<Entry*>(const_cast<const DataNodeView*>(this)->DataEnd<Entry>());
   }
 
-protected:
-
+private:
   template<int offset, class Type>
   const Type *GetOffset() const {
     return (Type*)(((const int8_t*)_block->data())+offset);
   }
 
-private:
-  DISALLOW_COPY_AND_ASSIGN(DataNodeView);
-
   std::unique_ptr<blockstore::Block> _block;
 
+  DISALLOW_COPY_AND_ASSIGN(DataNodeView);
+
 };
 
 }
diff --git a/src/test/blobstore/implementations/onblocks/impl/DataNodeViewTest.cpp b/src/test/blobstore/implementations/onblocks/impl/DataNodeViewTest.cpp
new file mode 100644
index 00000000..db4b74b7
--- /dev/null
+++ b/src/test/blobstore/implementations/onblocks/impl/DataNodeViewTest.cpp
@@ -0,0 +1,134 @@
+#include <gtest/gtest.h>
+
+#include "blockstore/implementations/inmemory/InMemoryBlockStore.h"
+#include "blockstore/implementations/inmemory/InMemoryBlock.h"
+#include "blobstore/implementations/onblocks/BlobStoreOnBlocks.h"
+#include "blobstore/implementations/onblocks/impl/DataNodeView.h"
+#include "test/testutils/DataBlockFixture.h"
+
+using ::testing::Test;
+using ::testing::WithParamInterface;
+using ::testing::Values;
+using std::unique_ptr;
+using std::make_unique;
+using std::string;
+
+using blockstore::BlockStore;
+using blockstore::inmemory::InMemoryBlockStore;
+using namespace blobstore;
+using namespace blobstore::onblocks;
+
+class DataNodeViewTest: public Test {
+public:
+  unique_ptr<BlockStore> blockStore = make_unique<InMemoryBlockStore>();
+};
+
+TEST_F(DataNodeViewTest, MagicNumberIsStored) {
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  {
+    DataNodeView view(std::move(block.block));
+    *view.MagicNumber() = 0x3F;
+  }
+  DataNodeView view(blockStore->load(block.key));
+  EXPECT_EQ(0x3F, *view.MagicNumber());
+}
+
+class DataNodeViewSizeTest: public DataNodeViewTest, public WithParamInterface<uint32_t> {
+};
+INSTANTIATE_TEST_CASE_P(DataNodeViewSizeTest, DataNodeViewSizeTest, Values(0, 50, 64, 1024, 1024*1024*1024));
+
+TEST_P(DataNodeViewSizeTest, SizeIsStored) {
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  {
+    DataNodeView view(std::move(block.block));
+    *view.Size() = GetParam();
+  }
+  DataNodeView view(blockStore->load(block.key));
+  EXPECT_EQ(GetParam(), *view.Size());
+}
+
+TEST_F(DataNodeViewTest, DataIsStored) {
+  DataBlockFixture randomData(DataNodeView::DATASIZE_BYTES);
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  {
+    DataNodeView view(std::move(block.block));
+    std::memcpy(view.DataBegin<uint8_t>(), randomData.data(), DataNodeView::DATASIZE_BYTES);
+  }
+  DataNodeView view(blockStore->load(block.key));
+  EXPECT_EQ(0, std::memcmp(view.DataBegin<uint8_t>(), randomData.data(), DataNodeView::DATASIZE_BYTES));
+}
+
+TEST_F(DataNodeViewTest, HeaderAndBodyDontOverlap) {
+  DataBlockFixture randomData(DataNodeView::DATASIZE_BYTES);
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  {
+    DataNodeView view(std::move(block.block));
+    *view.MagicNumber() = 0xAA;
+    *view.Size() = 1000000000u;
+    std::memcpy(view.DataBegin<uint8_t>(), randomData.data(), DataNodeView::DATASIZE_BYTES);
+  }
+  DataNodeView view(blockStore->load(block.key));
+  EXPECT_EQ(0xAA, *view.MagicNumber());
+  EXPECT_EQ(1000000000u, *view.Size());
+  EXPECT_EQ(0, std::memcmp(view.DataBegin<uint8_t>(), randomData.data(), DataNodeView::DATASIZE_BYTES));
+}
+
+TEST_F(DataNodeViewTest, DataBeginWorksWithOneByteEntries) {
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  uint8_t *blockBegin = (uint8_t*)block.block->data();
+  DataNodeView view(std::move(block.block));
+
+  EXPECT_EQ(blockBegin+view.HEADERSIZE_BYTES, view.DataBegin<uint8_t>());
+}
+
+TEST_F(DataNodeViewTest, DataBeginWorksWithEightByteEntries) {
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  uint8_t *blockBegin = (uint8_t*)block.block->data();
+  DataNodeView view(std::move(block.block));
+
+  EXPECT_EQ(blockBegin+view.HEADERSIZE_BYTES, (uint8_t*)view.DataBegin<uint64_t>());
+}
+
+TEST_F(DataNodeViewTest, DataEndWorksWithOneByteEntries) {
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  uint8_t *blockBegin = (uint8_t*)block.block->data();
+  DataNodeView view(std::move(block.block));
+
+  EXPECT_EQ(blockBegin+view.BLOCKSIZE_BYTES, view.DataEnd<uint8_t>());
+}
+
+TEST_F(DataNodeViewTest, DataEndWorksWithEightByteEntries) {
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  uint8_t *blockBegin = (uint8_t*)block.block->data();
+  DataNodeView view(std::move(block.block));
+
+  EXPECT_EQ(blockBegin+view.BLOCKSIZE_BYTES, (uint8_t*)view.DataEnd<uint64_t>());
+}
+
+struct SizedDataEntry {
+  uint8_t data[6];
+};
+BOOST_STATIC_ASSERT_MSG(DataNodeView::DATASIZE_BYTES % sizeof(SizedDataEntry) != 0,
+  "This test case only makes sense, if the data entries don't fill up the whole space. "
+  "There should be some space left at the end that is not used, because it isn't enough space for a full entry. "
+  "If this static assertion fails, please use a different size for SizedDataEntry.");
+
+TEST_F(DataNodeViewTest, DataBeginWorksWithStructEntries) {
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  uint8_t *blockBegin = (uint8_t*)block.block->data();
+  DataNodeView view(std::move(block.block));
+
+  EXPECT_EQ(blockBegin+view.HEADERSIZE_BYTES, (uint8_t*)view.DataBegin<SizedDataEntry>());
+}
+
+TEST_F(DataNodeViewTest, DataEndWorksWithStructByteEntries) {
+  auto block = blockStore->create(BlobStoreOnBlocks::BLOCKSIZE);
+  uint8_t *blockBegin = (uint8_t*)block.block->data();
+  DataNodeView view(std::move(block.block));
+
+  unsigned int numFittingEntries = view.DATASIZE_BYTES / sizeof(SizedDataEntry);
+
+  uint8_t *dataEnd = (uint8_t*)view.DataEnd<SizedDataEntry>();
+  EXPECT_EQ(blockBegin+view.HEADERSIZE_BYTES + numFittingEntries * sizeof(SizedDataEntry), dataEnd);
+  EXPECT_LT(dataEnd, blockBegin + view.BLOCKSIZE_BYTES);
+}