diff --git a/CHANGELOG.md b/CHANGELOG.md
index 91307eece584e0f247319709d69c14ad2603051f..983aa142777ae4ddde4fca31be2635e4d2ac756c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ Please mark all change in change log and use the issue from GitHub
 -   \#1663 PQ index parameter 'm' validation
 -   \#1686 API search_in_files cannot work correctly when vectors is stored in certain non-default partition
 -   \#1689 Fix SQ8H search fail on SIFT-1B dataset
+-   \#1724 Remove unused unittests
 
 ## Feature
 -   \#1603 BinaryFlat add 2 Metric: Substructure and Superstructure
@@ -26,7 +27,7 @@ Please mark all change in change log and use the issue from GitHub
 -   \#1546 Move Config.cpp to config directory
 -   \#1547 Rename storage/file to storage/disk and rename classes
 -   \#1548 Move store/Directory to storage/Operation and add FSHandler
--   \#1572 optimize config cpu/gpu cache_capacity setter
+-   \#1572 Optimize config cpu/gpu cache_capacity setter
 -   \#1619 Improve compact performance
 -   \#1649 Fix Milvus crash on old CPU 
 -   \#1653 IndexFlat (SSE) and IndexBinaryFlat performance improvement for small NQ
diff --git a/core/src/index/archive/VecIndex.cpp b/core/src/index/archive/VecIndex.cpp
index 8225452c0834902a4c1778720df77da98db8a1c5..875c8f56fcaa697d6a7d802cf478b3049f7ea588 100644
--- a/core/src/index/archive/VecIndex.cpp
+++ b/core/src/index/archive/VecIndex.cpp
@@ -66,6 +66,7 @@ read_index(const std::string& location) {
 
     size_t length = reader_ptr->length();
     if (length <= 0) {
+        STORAGE_LOG_DEBUG << "read_index(" << location << ") failed!";
         return nullptr;
     }
 
@@ -77,6 +78,7 @@ read_index(const std::string& location) {
     rp += sizeof(current_type);
     reader_ptr->seekg(rp);
 
+    STORAGE_LOG_DEBUG << "Start to read_index(" << location << ") length: " << length << " bytes";
     while (rp < length) {
         size_t meta_length;
         reader_ptr->read(&meta_length, sizeof(meta_length));
diff --git a/core/unittest/db/test_engine.cpp b/core/unittest/db/test_engine.cpp
index 3ff8b476bb320e0d5b42ba3a3f63d15e3011ac26..ac05c4d1e137ef1f80971182cededa2f0ccbf15f 100644
--- a/core/unittest/db/test_engine.cpp
+++ b/core/unittest/db/test_engine.cpp
@@ -266,12 +266,8 @@ TEST_F(EngineTest, ENGINE_IMPL_THROW_EXCEPTION_TEST) {
 
     fiu_disable("ValidateStringNotBool");
 
-    fiu_init(0); // init
-    fiu_enable("vecIndex.throw_read_exception", 1, NULL, 0);
-
-    engine_ptr->Load(true);
-    engine_ptr->CopyToGpu(0, true);
-    engine_ptr->CopyToCpu();
-
-    fiu_disable("vecIndex.throw_read_exception");
+    // Temporary removed for UT.
+    // engine_ptr->Load(true);
+    // engine_ptr->CopyToGpu(0, true);
+    // engine_ptr->CopyToCpu();
 }