diff --git a/scm-core/src/main/java/sonia/scm/store/BlobStore.java b/scm-core/src/main/java/sonia/scm/store/BlobStore.java
index eb623e240f..3626871a9a 100644
--- a/scm-core/src/main/java/sonia/scm/store/BlobStore.java
+++ b/scm-core/src/main/java/sonia/scm/store/BlobStore.java
@@ -40,7 +40,7 @@ import java.util.List;
  *
  * @author Sebastian Sdorra
  * @since 1.23
- * 
+ *
  * @apiviz.uses sonia.scm.store.Blob
  */
 public interface BlobStore extends StoreBase<Blob>
@@ -61,6 +61,9 @@ public interface BlobStore extends StoreBase<Blob>
    * @param id id of the new blob
    *
    * @return new blob
+   *
+   * @throws EntryAllreadyExistsStoreException if a blob with given id already
+   *   exists
    */
   public Blob create(String id);
 
diff --git a/scm-core/src/main/java/sonia/scm/store/EntryAlreadyExistsStoreException.java b/scm-core/src/main/java/sonia/scm/store/EntryAlreadyExistsStoreException.java
new file mode 100644
index 0000000000..7eaf4c3f5a
--- /dev/null
+++ b/scm-core/src/main/java/sonia/scm/store/EntryAlreadyExistsStoreException.java
@@ -0,0 +1,59 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.store;
+
+/**
+ * This exception is thrown on a create method if an entry with the given id
+ * already exists.
+ *
+ * @author Sebastian Sdorra
+ * @since 1.23
+ */
+public class EntryAlreadyExistsStoreException extends StoreException
+{
+
+  /** Field description */
+  private static final long serialVersionUID = 7016781091599951287L;
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * Constructs new EntryAllreadyExistsStoreException.
+   *
+   *
+   * @param message message for the exception
+   */
+  public EntryAlreadyExistsStoreException(String message)
+  {
+    super(message);
+  }
+}
diff --git a/scm-dao-xml/src/main/java/sonia/scm/store/FileBlobStore.java b/scm-dao-xml/src/main/java/sonia/scm/store/FileBlobStore.java
index df400bd5f8..193ed8e43b 100644
--- a/scm-dao-xml/src/main/java/sonia/scm/store/FileBlobStore.java
+++ b/scm-dao-xml/src/main/java/sonia/scm/store/FileBlobStore.java
@@ -116,9 +116,10 @@ public class FileBlobStore extends FileBasedStore<Blob> implements BlobStore
     {
       if (file.exists())
       {
-        throw new StoreException("blob allready exists");
-      } 
-      else if ( !file.createNewFile() )
+        throw new EntryAlreadyExistsStoreException(
+          "blob with id ".concat(id).concat(" allready exists"));
+      }
+      else if (!file.createNewFile())
       {
         throw new StoreException("could not create blob for id ".concat(id));
       }
diff --git a/scm-test/src/main/java/sonia/scm/store/BlobStoreTestBase.java b/scm-test/src/main/java/sonia/scm/store/BlobStoreTestBase.java
index 6d0433365e..ba00f64985 100644
--- a/scm-test/src/main/java/sonia/scm/store/BlobStoreTestBase.java
+++ b/scm-test/src/main/java/sonia/scm/store/BlobStoreTestBase.java
@@ -122,6 +122,17 @@ public abstract class BlobStoreTestBase extends AbstractTestBase
     assertEquals("Other Text", read(blob));
   }
 
+  /**
+   * Method description
+   *
+   */
+  @Test(expected = EntryAlreadyExistsStoreException.class)
+  public void testCreateAlreadyExistingEntry()
+  {
+    assertNotNull(store.create("1"));
+    store.create("1");
+  }
+
   /**
    * Method description
    *