diff --git a/db/blob/db_blob_index_test.cc b/db/blob/db_blob_index_test.cc
index 24862f771..b235bbfa9 100644
--- a/db/blob/db_blob_index_test.cc
+++ b/db/blob/db_blob_index_test.cc
@@ -41,7 +41,8 @@ class DBBlobIndexTest : public DBTestBase {
                                        Tier::kImmutableMemtables,
                                        Tier::kL0SstFile, Tier::kLnSstFile};
 
-  DBBlobIndexTest() : DBTestBase("/db_blob_index_test") {}
+  DBBlobIndexTest()
+      : DBTestBase("/db_blob_index_test", /*env_do_fsync=*/true) {}
 
   ColumnFamilyHandle* cfh() { return dbfull()->DefaultColumnFamily(); }
 
diff --git a/db/db_basic_test.cc b/db/db_basic_test.cc
index e9584b568..9f96ae9f7 100644
--- a/db/db_basic_test.cc
+++ b/db/db_basic_test.cc
@@ -27,7 +27,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBBasicTest : public DBTestBase {
  public:
-  DBBasicTest() : DBTestBase("/db_basic_test") {}
+  DBBasicTest() : DBTestBase("/db_basic_test", /*env_do_fsync=*/true) {}
 };
 
 TEST_F(DBBasicTest, OpenWhenOpen) {
@@ -2352,7 +2352,7 @@ class DBBasicTestMultiGet : public DBTestBase {
   DBBasicTestMultiGet(std::string test_dir, int num_cfs, bool compressed_cache,
                       bool uncompressed_cache, bool _compression_enabled,
                       bool _fill_cache, uint32_t compression_parallel_threads)
-      : DBTestBase(test_dir) {
+      : DBTestBase(test_dir, /*env_do_fsync=*/true) {
     compression_enabled_ = _compression_enabled;
     fill_cache_ = _fill_cache;
 
diff --git a/db/db_block_cache_test.cc b/db/db_block_cache_test.cc
index 0841a655e..426a1930b 100644
--- a/db/db_block_cache_test.cc
+++ b/db/db_block_cache_test.cc
@@ -32,7 +32,8 @@ class DBBlockCacheTest : public DBTestBase {
   const size_t kNumBlocks = 10;
   const size_t kValueSize = 100;
 
-  DBBlockCacheTest() : DBTestBase("/db_block_cache_test") {}
+  DBBlockCacheTest()
+      : DBTestBase("/db_block_cache_test", /*env_do_fsync=*/true) {}
 
   BlockBasedTableOptions GetTableOptions() {
     BlockBasedTableOptions table_options;
diff --git a/db/db_bloom_filter_test.cc b/db/db_bloom_filter_test.cc
index 79f2bcbae..2231af6da 100644
--- a/db/db_bloom_filter_test.cc
+++ b/db/db_bloom_filter_test.cc
@@ -23,7 +23,8 @@ using BFP = BloomFilterPolicy;
 
 class DBBloomFilterTest : public DBTestBase {
  public:
-  DBBloomFilterTest() : DBTestBase("/db_bloom_filter_test") {}
+  DBBloomFilterTest()
+      : DBTestBase("/db_bloom_filter_test", /*env_do_fsync=*/true) {}
 };
 
 class DBBloomFilterTestWithParam : public DBTestBase,
@@ -36,7 +37,8 @@ class DBBloomFilterTestWithParam : public DBTestBase,
   uint32_t format_version_;
 
  public:
-  DBBloomFilterTestWithParam() : DBTestBase("/db_bloom_filter_tests") {}
+  DBBloomFilterTestWithParam()
+      : DBTestBase("/db_bloom_filter_tests", /*env_do_fsync=*/true) {}
 
   ~DBBloomFilterTestWithParam() override {}
 
@@ -1039,7 +1041,7 @@ class DBBloomFilterTestVaryPrefixAndFormatVer
 
  public:
   DBBloomFilterTestVaryPrefixAndFormatVer()
-      : DBTestBase("/db_bloom_filter_tests") {}
+      : DBTestBase("/db_bloom_filter_tests", /*env_do_fsync=*/true) {}
 
   ~DBBloomFilterTestVaryPrefixAndFormatVer() override {}
 
diff --git a/db/db_compaction_filter_test.cc b/db/db_compaction_filter_test.cc
index a708c0b1a..d357e634f 100644
--- a/db/db_compaction_filter_test.cc
+++ b/db/db_compaction_filter_test.cc
@@ -21,7 +21,8 @@ static std::string NEW_VALUE = "NewValue";
 
 class DBTestCompactionFilter : public DBTestBase {
  public:
-  DBTestCompactionFilter() : DBTestBase("/db_compaction_filter_test") {}
+  DBTestCompactionFilter()
+      : DBTestBase("/db_compaction_filter_test", /*env_do_fsync=*/true) {}
 };
 
 // Param variant of DBTestBase::ChangeCompactOptions
diff --git a/db/db_compaction_test.cc b/db/db_compaction_test.cc
index eb86ec2dc..3946d36b5 100644
--- a/db/db_compaction_test.cc
+++ b/db/db_compaction_test.cc
@@ -25,14 +25,16 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBCompactionTest : public DBTestBase {
  public:
-  DBCompactionTest() : DBTestBase("/db_compaction_test") {}
+  DBCompactionTest()
+      : DBTestBase("/db_compaction_test", /*env_do_fsync=*/true) {}
 };
 
 class DBCompactionTestWithParam
     : public DBTestBase,
       public testing::WithParamInterface<std::tuple<uint32_t, bool>> {
  public:
-  DBCompactionTestWithParam() : DBTestBase("/db_compaction_test") {
+  DBCompactionTestWithParam()
+      : DBTestBase("/db_compaction_test", /*env_do_fsync=*/true) {
     max_subcompactions_ = std::get<0>(GetParam());
     exclusive_manual_compaction_ = std::get<1>(GetParam());
   }
@@ -4753,7 +4755,8 @@ INSTANTIATE_TEST_CASE_P(DBCompactionDirectIOTest, DBCompactionDirectIOTest,
 class CompactionPriTest : public DBTestBase,
                           public testing::WithParamInterface<uint32_t> {
  public:
-  CompactionPriTest() : DBTestBase("/compaction_pri_test") {
+  CompactionPriTest()
+      : DBTestBase("/compaction_pri_test", /*env_do_fsync=*/true) {
     compaction_pri_ = GetParam();
   }
 
diff --git a/db/db_dynamic_level_test.cc b/db/db_dynamic_level_test.cc
index ec059feb9..cba997eb5 100644
--- a/db/db_dynamic_level_test.cc
+++ b/db/db_dynamic_level_test.cc
@@ -19,7 +19,8 @@
 namespace ROCKSDB_NAMESPACE {
 class DBTestDynamicLevel : public DBTestBase {
  public:
-  DBTestDynamicLevel() : DBTestBase("/db_dynamic_level_test") {}
+  DBTestDynamicLevel()
+      : DBTestBase("/db_dynamic_level_test", /*env_do_fsync=*/true) {}
 };
 
 TEST_F(DBTestDynamicLevel, DynamicLevelMaxBytesBase) {
diff --git a/db/db_encryption_test.cc b/db/db_encryption_test.cc
index b1f3ce23f..dddc83307 100644
--- a/db/db_encryption_test.cc
+++ b/db/db_encryption_test.cc
@@ -16,7 +16,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBEncryptionTest : public DBTestBase {
  public:
-  DBEncryptionTest() : DBTestBase("/db_encryption_test") {}
+  DBEncryptionTest()
+      : DBTestBase("/db_encryption_test", /*env_do_fsync=*/true) {}
 };
 
 #ifndef ROCKSDB_LITE
diff --git a/db/db_flush_test.cc b/db/db_flush_test.cc
index 9485d5f22..ca8e69d29 100644
--- a/db/db_flush_test.cc
+++ b/db/db_flush_test.cc
@@ -22,7 +22,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBFlushTest : public DBTestBase {
  public:
-  DBFlushTest() : DBTestBase("/db_flush_test") {}
+  DBFlushTest() : DBTestBase("/db_flush_test", /*env_do_fsync=*/true) {}
 };
 
 class DBFlushDirectIOTest : public DBFlushTest,
diff --git a/db/db_impl/db_secondary_test.cc b/db/db_impl/db_secondary_test.cc
index d54a52493..7a412aedc 100644
--- a/db/db_impl/db_secondary_test.cc
+++ b/db/db_impl/db_secondary_test.cc
@@ -19,7 +19,7 @@ namespace ROCKSDB_NAMESPACE {
 class DBSecondaryTest : public DBTestBase {
  public:
   DBSecondaryTest()
-      : DBTestBase("/db_secondary_test"),
+      : DBTestBase("/db_secondary_test", /*env_do_fsync=*/true),
         secondary_path_(),
         handles_secondary_(),
         db_secondary_(nullptr) {
diff --git a/db/db_inplace_update_test.cc b/db/db_inplace_update_test.cc
index 26405864e..944ca24a7 100644
--- a/db/db_inplace_update_test.cc
+++ b/db/db_inplace_update_test.cc
@@ -13,7 +13,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBTestInPlaceUpdate : public DBTestBase {
  public:
-  DBTestInPlaceUpdate() : DBTestBase("/db_inplace_update_test") {}
+  DBTestInPlaceUpdate()
+      : DBTestBase("/db_inplace_update_test", /*env_do_fsync=*/true) {}
 };
 
 TEST_F(DBTestInPlaceUpdate, InPlaceUpdate) {
diff --git a/db/db_io_failure_test.cc b/db/db_io_failure_test.cc
index f8d562447..fa8700347 100644
--- a/db/db_io_failure_test.cc
+++ b/db/db_io_failure_test.cc
@@ -14,7 +14,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBIOFailureTest : public DBTestBase {
  public:
-  DBIOFailureTest() : DBTestBase("/db_io_failure_test") {}
+  DBIOFailureTest()
+      : DBTestBase("/db_io_failure_test", /*env_do_fsync=*/true) {}
 };
 
 #ifndef ROCKSDB_LITE
diff --git a/db/db_iterator_test.cc b/db/db_iterator_test.cc
index dcef1f897..c66ca2a9a 100644
--- a/db/db_iterator_test.cc
+++ b/db/db_iterator_test.cc
@@ -33,7 +33,7 @@ class DummyReadCallback : public ReadCallback {
 class DBIteratorTest : public DBTestBase,
                        public testing::WithParamInterface<bool> {
  public:
-  DBIteratorTest() : DBTestBase("/db_iterator_test") {}
+  DBIteratorTest() : DBTestBase("/db_iterator_test", /*env_do_fsync=*/true) {}
 
   Iterator* NewIterator(const ReadOptions& read_options,
                         ColumnFamilyHandle* column_family = nullptr) {
diff --git a/db/db_log_iter_test.cc b/db/db_log_iter_test.cc
index 1f9ff0d45..51d232a6a 100644
--- a/db/db_log_iter_test.cc
+++ b/db/db_log_iter_test.cc
@@ -19,7 +19,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBTestXactLogIterator : public DBTestBase {
  public:
-  DBTestXactLogIterator() : DBTestBase("/db_log_iter_test") {}
+  DBTestXactLogIterator()
+      : DBTestBase("/db_log_iter_test", /*env_do_fsync=*/true) {}
 
   std::unique_ptr<TransactionLogIterator> OpenTransactionLogIter(
       const SequenceNumber seq) {
diff --git a/db/db_memtable_test.cc b/db/db_memtable_test.cc
index 5b8a9b7b8..99763e351 100644
--- a/db/db_memtable_test.cc
+++ b/db/db_memtable_test.cc
@@ -17,7 +17,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBMemTableTest : public DBTestBase {
  public:
-  DBMemTableTest() : DBTestBase("/db_memtable_test") {}
+  DBMemTableTest() : DBTestBase("/db_memtable_test", /*env_do_fsync=*/true) {}
 };
 
 class MockMemTableRep : public MemTableRep {
diff --git a/db/db_merge_operand_test.cc b/db/db_merge_operand_test.cc
index a0ab34e01..2f1e8ead8 100644
--- a/db/db_merge_operand_test.cc
+++ b/db/db_merge_operand_test.cc
@@ -21,7 +21,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBMergeOperandTest : public DBTestBase {
  public:
-  DBMergeOperandTest() : DBTestBase("/db_merge_operand_test") {}
+  DBMergeOperandTest()
+      : DBTestBase("/db_merge_operand_test", /*env_do_fsync=*/true) {}
 };
 
 TEST_F(DBMergeOperandTest, GetMergeOperandsBasic) {
diff --git a/db/db_merge_operator_test.cc b/db/db_merge_operator_test.cc
index 4f762468d..9fb527c08 100644
--- a/db/db_merge_operator_test.cc
+++ b/db/db_merge_operator_test.cc
@@ -35,7 +35,8 @@ class TestReadCallback : public ReadCallback {
 // Test merge operator functionality.
 class DBMergeOperatorTest : public DBTestBase {
  public:
-  DBMergeOperatorTest() : DBTestBase("/db_merge_operator_test") {}
+  DBMergeOperatorTest()
+      : DBTestBase("/db_merge_operator_test", /*env_do_fsync=*/true) {}
 
   std::string GetWithReadCallback(SnapshotChecker* snapshot_checker,
                                   const Slice& key,
diff --git a/db/db_options_test.cc b/db/db_options_test.cc
index 8cc09ec54..add2e72a2 100644
--- a/db/db_options_test.cc
+++ b/db/db_options_test.cc
@@ -27,7 +27,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBOptionsTest : public DBTestBase {
  public:
-  DBOptionsTest() : DBTestBase("/db_options_test") {}
+  DBOptionsTest() : DBTestBase("/db_options_test", /*env_do_fsync=*/true) {}
 
 #ifndef ROCKSDB_LITE
   std::unordered_map<std::string, std::string> GetMutableDBOptionsMap(
diff --git a/db/db_properties_test.cc b/db/db_properties_test.cc
index 50dc3efef..afb503285 100644
--- a/db/db_properties_test.cc
+++ b/db/db_properties_test.cc
@@ -26,7 +26,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBPropertiesTest : public DBTestBase {
  public:
-  DBPropertiesTest() : DBTestBase("/db_properties_test") {}
+  DBPropertiesTest()
+      : DBTestBase("/db_properties_test", /*env_do_fsync=*/true) {}
 };
 
 #ifndef ROCKSDB_LITE
diff --git a/db/db_range_del_test.cc b/db/db_range_del_test.cc
index 83fb27ff3..3932f4185 100644
--- a/db/db_range_del_test.cc
+++ b/db/db_range_del_test.cc
@@ -13,7 +13,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBRangeDelTest : public DBTestBase {
  public:
-  DBRangeDelTest() : DBTestBase("/db_range_del_test") {}
+  DBRangeDelTest() : DBTestBase("/db_range_del_test", /*env_do_fsync=*/true) {}
 
   std::string GetNumericStr(int key) {
     uint64_t uint64_key = static_cast<uint64_t>(key);
diff --git a/db/db_sst_test.cc b/db/db_sst_test.cc
index 687d3b852..27a7f7636 100644
--- a/db/db_sst_test.cc
+++ b/db/db_sst_test.cc
@@ -17,7 +17,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBSSTTest : public DBTestBase {
  public:
-  DBSSTTest() : DBTestBase("/db_sst_test") {}
+  DBSSTTest() : DBTestBase("/db_sst_test", /*env_do_fsync=*/true) {}
 };
 
 #ifndef ROCKSDB_LITE
diff --git a/db/db_statistics_test.cc b/db/db_statistics_test.cc
index 8fbbb96d5..5a7c8ea66 100644
--- a/db/db_statistics_test.cc
+++ b/db/db_statistics_test.cc
@@ -14,7 +14,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBStatisticsTest : public DBTestBase {
  public:
-  DBStatisticsTest() : DBTestBase("/db_statistics_test") {}
+  DBStatisticsTest()
+      : DBTestBase("/db_statistics_test", /*env_do_fsync=*/true) {}
 };
 
 TEST_F(DBStatisticsTest, CompressionStatsTest) {
diff --git a/db/db_table_properties_test.cc b/db/db_table_properties_test.cc
index 98512e22f..17bdf8268 100644
--- a/db/db_table_properties_test.cc
+++ b/db/db_table_properties_test.cc
@@ -48,7 +48,8 @@ void VerifyTableProperties(DB* db, uint64_t expected_entries_size) {
 class DBTablePropertiesTest : public DBTestBase,
                               public testing::WithParamInterface<std::string> {
  public:
-  DBTablePropertiesTest() : DBTestBase("/db_table_properties_test") {}
+  DBTablePropertiesTest()
+      : DBTestBase("/db_table_properties_test", /*env_do_fsync=*/true) {}
   TablePropertiesCollection TestGetPropertiesOfTablesInRange(
       std::vector<Range> ranges, std::size_t* num_properties = nullptr,
       std::size_t* num_files = nullptr);
diff --git a/db/db_tailing_iter_test.cc b/db/db_tailing_iter_test.cc
index 39988638b..f33b7cb13 100644
--- a/db/db_tailing_iter_test.cc
+++ b/db/db_tailing_iter_test.cc
@@ -20,7 +20,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBTestTailingIterator : public DBTestBase {
  public:
-  DBTestTailingIterator() : DBTestBase("/db_tailing_iterator_test") {}
+  DBTestTailingIterator()
+      : DBTestBase("/db_tailing_iterator_test", /*env_do_fsync=*/true) {}
 };
 
 TEST_F(DBTestTailingIterator, TailingIteratorSingle) {
diff --git a/db/db_test.cc b/db/db_test.cc
index 4af91c990..d14f400fe 100644
--- a/db/db_test.cc
+++ b/db/db_test.cc
@@ -70,9 +70,12 @@
 
 namespace ROCKSDB_NAMESPACE {
 
+// Note that whole DBTest and its child classes disable fsync on files
+// and directories for speed.
+// If fsync needs to be covered in a test, put it in other places.
 class DBTest : public DBTestBase {
  public:
-  DBTest() : DBTestBase("/db_test") {}
+  DBTest() : DBTestBase("/db_test", /*env_do_fsync=*/false) {}
 };
 
 class DBTestWithParam
@@ -1790,7 +1793,6 @@ TEST_F(DBTest, Snapshot) {
 TEST_F(DBTest, HiddenValuesAreRemoved) {
   anon::OptionsOverride options_override;
   options_override.skip_policy = kSkipNoSnapshot;
-  env_->skip_fsync_ = true;
   do {
     Options options = CurrentOptions(options_override);
     CreateAndReopenWithCF({"pikachu"}, options);
@@ -3995,7 +3997,6 @@ TEST_F(DBTest, DynamicMemtableOptions) {
   const uint64_t k128KB = 1 << 17;
   const uint64_t k5KB = 5 * 1024;
   Options options;
-  env_->skip_fsync_ = true;
   options.env = env_;
   options.create_if_missing = true;
   options.compression = kNoCompression;
@@ -5142,7 +5143,6 @@ TEST_F(DBTest, DynamicUniversalCompactionOptions) {
 
 TEST_F(DBTest, FileCreationRandomFailure) {
   Options options;
-  env_->skip_fsync_ = true;
   options.env = env_;
   options.create_if_missing = true;
   options.write_buffer_size = 100000;  // Small write buffer
@@ -5502,7 +5502,6 @@ TEST_F(DBTest, MergeTestTime) {
 #ifndef ROCKSDB_LITE
 TEST_P(DBTestWithParam, MergeCompactionTimeTest) {
   SetPerfLevel(kEnableTime);
-  env_->skip_fsync_ = true;
   Options options = CurrentOptions();
   options.compaction_filter_factory = std::make_shared<KeepFilterFactory>();
   options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
diff --git a/db/db_test2.cc b/db/db_test2.cc
index fd2933b8c..a48e66fde 100644
--- a/db/db_test2.cc
+++ b/db/db_test2.cc
@@ -22,7 +22,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBTest2 : public DBTestBase {
  public:
-  DBTest2() : DBTestBase("/db_test2") {}
+  DBTest2() : DBTestBase("/db_test2", /*env_do_fsync=*/true) {}
 };
 
 #ifndef ROCKSDB_LITE
@@ -92,7 +92,8 @@ class TestReadOnlyWithCompressedCache
       public testing::WithParamInterface<std::tuple<int, bool>> {
  public:
   TestReadOnlyWithCompressedCache()
-      : DBTestBase("/test_readonly_with_compressed_cache") {
+      : DBTestBase("/test_readonly_with_compressed_cache",
+                   /*env_do_fsync=*/true) {
     max_open_files_ = std::get<0>(GetParam());
     use_mmap_ = std::get<1>(GetParam());
   }
@@ -183,7 +184,7 @@ class PrefixFullBloomWithReverseComparator
       public ::testing::WithParamInterface<bool> {
  public:
   PrefixFullBloomWithReverseComparator()
-      : DBTestBase("/prefix_bloom_reverse") {}
+      : DBTestBase("/prefix_bloom_reverse", /*env_do_fsync=*/true) {}
   void SetUp() override { if_cache_filter_ = GetParam(); }
   bool if_cache_filter_;
 };
@@ -323,7 +324,7 @@ class DBTestSharedWriteBufferAcrossCFs
       public testing::WithParamInterface<std::tuple<bool, bool>> {
  public:
   DBTestSharedWriteBufferAcrossCFs()
-      : DBTestBase("/db_test_shared_write_buffer") {}
+      : DBTestBase("/db_test_shared_write_buffer", /*env_do_fsync=*/true) {}
   void SetUp() override {
     use_old_interface_ = std::get<0>(GetParam());
     cost_cache_ = std::get<1>(GetParam());
@@ -1790,7 +1791,8 @@ class PinL0IndexAndFilterBlocksTest
     : public DBTestBase,
       public testing::WithParamInterface<std::tuple<bool, bool>> {
  public:
-  PinL0IndexAndFilterBlocksTest() : DBTestBase("/db_pin_l0_index_bloom_test") {}
+  PinL0IndexAndFilterBlocksTest()
+      : DBTestBase("/db_pin_l0_index_bloom_test", /*env_do_fsync=*/true) {}
   void SetUp() override {
     infinite_max_files_ = std::get<0>(GetParam());
     disallow_preload_ = std::get<1>(GetParam());
diff --git a/db/db_test_util.cc b/db/db_test_util.cc
index c2c1d44ea..0a61d56ad 100644
--- a/db/db_test_util.cc
+++ b/db/db_test_util.cc
@@ -56,7 +56,7 @@ SpecialEnv::SpecialEnv(Env* base)
 ROT13BlockCipher rot13Cipher_(16);
 #endif  // ROCKSDB_LITE
 
-DBTestBase::DBTestBase(const std::string path)
+DBTestBase::DBTestBase(const std::string path, bool env_do_fsync)
     : mem_env_(nullptr), encrypted_env_(nullptr), option_config_(kDefault) {
   Env* base_env = Env::Default();
 #ifndef ROCKSDB_LITE
@@ -83,6 +83,7 @@ DBTestBase::DBTestBase(const std::string path)
                                        : (mem_env_ ? mem_env_ : base_env));
   env_->SetBackgroundThreads(1, Env::LOW);
   env_->SetBackgroundThreads(1, Env::HIGH);
+  env_->skip_fsync_ = !env_do_fsync;
   dbname_ = test::PerThreadDBPath(env_, path);
   alternative_wal_dir_ = dbname_ + "/wal";
   alternative_db_log_dir_ = dbname_ + "/db_log_dir";
diff --git a/db/db_test_util.h b/db/db_test_util.h
index 7a40a1346..4330b9cfb 100644
--- a/db/db_test_util.h
+++ b/db/db_test_util.h
@@ -872,7 +872,10 @@ class DBTestBase : public testing::Test {
       // requires.
       kSkipMmapReads;
 
-  explicit DBTestBase(const std::string path);
+  // `env_do_fsync` decides whether the special Env would do real
+  // fsync for files and directories. Skipping fsync can speed up
+  // tests, but won't cover the exact fsync logic.
+  DBTestBase(const std::string path, bool env_do_fsync);
 
   ~DBTestBase();
 
diff --git a/db/db_universal_compaction_test.cc b/db/db_universal_compaction_test.cc
index 889e380dd..40b975280 100644
--- a/db/db_universal_compaction_test.cc
+++ b/db/db_universal_compaction_test.cc
@@ -25,8 +25,8 @@ class DBTestUniversalCompactionBase
     : public DBTestBase,
       public ::testing::WithParamInterface<std::tuple<int, bool>> {
  public:
-  explicit DBTestUniversalCompactionBase(
-      const std::string& path) : DBTestBase(path) {}
+  explicit DBTestUniversalCompactionBase(const std::string& path)
+      : DBTestBase(path, /*env_do_fsync=*/true) {}
   void SetUp() override {
     num_levels_ = std::get<0>(GetParam());
     exclusive_manual_compaction_ = std::get<1>(GetParam());
@@ -43,7 +43,8 @@ class DBTestUniversalCompaction : public DBTestUniversalCompactionBase {
 
 class DBTestUniversalCompaction2 : public DBTestBase {
  public:
-  DBTestUniversalCompaction2() : DBTestBase("/db_universal_compaction_test2") {}
+  DBTestUniversalCompaction2()
+      : DBTestBase("/db_universal_compaction_test2", /*env_do_fsync=*/true) {}
 };
 
 namespace {
diff --git a/db/db_wal_test.cc b/db/db_wal_test.cc
index f2f661c30..9fad7f6bc 100644
--- a/db/db_wal_test.cc
+++ b/db/db_wal_test.cc
@@ -18,7 +18,7 @@
 namespace ROCKSDB_NAMESPACE {
 class DBWALTest : public DBTestBase {
  public:
-  DBWALTest() : DBTestBase("/db_wal_test") {}
+  DBWALTest() : DBTestBase("/db_wal_test", /*env_do_fsync=*/true) {}
 
 #if defined(ROCKSDB_PLATFORM_POSIX)
   uint64_t GetAllocatedFileSize(std::string file_name) {
@@ -86,7 +86,8 @@ class EnrichedSpecialEnv : public SpecialEnv {
 
 class DBWALTestWithEnrichedEnv : public DBTestBase {
  public:
-  DBWALTestWithEnrichedEnv() : DBTestBase("/db_wal_test") {
+  DBWALTestWithEnrichedEnv()
+      : DBTestBase("/db_wal_test", /*env_do_fsync=*/true) {
     enriched_env_ = new EnrichedSpecialEnv(env_->target());
     auto options = CurrentOptions();
     options.env = enriched_env_;
diff --git a/db/db_with_timestamp_basic_test.cc b/db/db_with_timestamp_basic_test.cc
index a2a7313af..c431fc673 100644
--- a/db/db_with_timestamp_basic_test.cc
+++ b/db/db_with_timestamp_basic_test.cc
@@ -22,7 +22,7 @@ namespace ROCKSDB_NAMESPACE {
 class DBBasicTestWithTimestampBase : public DBTestBase {
  public:
   explicit DBBasicTestWithTimestampBase(const std::string& dbname)
-      : DBTestBase(dbname) {}
+      : DBTestBase(dbname, /*env_do_fsync=*/true) {}
 
  protected:
   static std::string Key1(uint64_t k) {
diff --git a/db/db_with_timestamp_compaction_test.cc b/db/db_with_timestamp_compaction_test.cc
index f5cc54df1..6b74fa21f 100644
--- a/db/db_with_timestamp_compaction_test.cc
+++ b/db/db_with_timestamp_compaction_test.cc
@@ -31,7 +31,7 @@ std::string Timestamp(uint64_t ts) {
 class TimestampCompatibleCompactionTest : public DBTestBase {
  public:
   TimestampCompatibleCompactionTest()
-      : DBTestBase("/ts_compatible_compaction_test") {}
+      : DBTestBase("/ts_compatible_compaction_test", /*env_do_fsync=*/true) {}
 
   std::string Get(const std::string& key, uint64_t ts) {
     ReadOptions read_opts;
diff --git a/db/db_write_test.cc b/db/db_write_test.cc
index cc1aaac08..7f05ad7ac 100644
--- a/db/db_write_test.cc
+++ b/db/db_write_test.cc
@@ -22,7 +22,7 @@ namespace ROCKSDB_NAMESPACE {
 // Test variations of WriteImpl.
 class DBWriteTest : public DBTestBase, public testing::WithParamInterface<int> {
  public:
-  DBWriteTest() : DBTestBase("/db_write_test") {}
+  DBWriteTest() : DBTestBase("/db_write_test", /*env_do_fsync=*/true) {}
 
   Options GetOptions() { return DBTestBase::GetOptions(GetParam()); }
 
diff --git a/db/deletefile_test.cc b/db/deletefile_test.cc
index f202388c0..635951a1e 100644
--- a/db/deletefile_test.cc
+++ b/db/deletefile_test.cc
@@ -35,7 +35,7 @@ class DeleteFileTest : public DBTestBase {
   const std::string wal_dir_;
 
   DeleteFileTest()
-      : DBTestBase("/deletefile_test"),
+      : DBTestBase("/deletefile_test", /*env_do_fsync=*/true),
         numlevels_(7),
         wal_dir_(dbname_ + "/wal_files") {}
 
diff --git a/db/error_handler_fs_test.cc b/db/error_handler_fs_test.cc
index 912baa1ba..5ad0a5629 100644
--- a/db/error_handler_fs_test.cc
+++ b/db/error_handler_fs_test.cc
@@ -23,7 +23,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class DBErrorHandlingFSTest : public DBTestBase {
  public:
-  DBErrorHandlingFSTest() : DBTestBase("/db_error_handling_fs_test") {}
+  DBErrorHandlingFSTest()
+      : DBTestBase("/db_error_handling_fs_test", /*env_do_fsync=*/true) {}
 
   std::string GetManifestNameFromLiveFiles() {
     std::vector<std::string> live_files;
diff --git a/db/external_sst_file_basic_test.cc b/db/external_sst_file_basic_test.cc
index 7e62963ec..1745f57ad 100644
--- a/db/external_sst_file_basic_test.cc
+++ b/db/external_sst_file_basic_test.cc
@@ -20,7 +20,8 @@ class ExternalSSTFileBasicTest
     : public DBTestBase,
       public ::testing::WithParamInterface<std::tuple<bool, bool>> {
  public:
-  ExternalSSTFileBasicTest() : DBTestBase("/external_sst_file_basic_test") {
+  ExternalSSTFileBasicTest()
+      : DBTestBase("/external_sst_file_basic_test", /*env_do_fsync=*/true) {
     sst_files_dir_ = dbname_ + "/sst_files/";
     fault_injection_test_env_.reset(new FaultInjectionTestEnv(Env::Default()));
     DestroyAndRecreateExternalSSTFilesDir();
diff --git a/db/external_sst_file_test.cc b/db/external_sst_file_test.cc
index 649bf7ac2..d64bebbe6 100644
--- a/db/external_sst_file_test.cc
+++ b/db/external_sst_file_test.cc
@@ -43,7 +43,7 @@ class ExternSSTFileLinkFailFallbackTest
       public ::testing::WithParamInterface<std::tuple<bool, bool>> {
  public:
   ExternSSTFileLinkFailFallbackTest()
-      : DBTestBase("/external_sst_file_test"),
+      : DBTestBase("/external_sst_file_test", /*env_do_fsync=*/true),
         test_env_(new ExternalSSTTestEnv(env_, true)) {
     sst_files_dir_ = dbname_ + "/sst_files/";
     test::DestroyDir(env_, sst_files_dir_);
@@ -71,7 +71,8 @@ class ExternalSSTFileTest
     : public DBTestBase,
       public ::testing::WithParamInterface<std::tuple<bool, bool>> {
  public:
-  ExternalSSTFileTest() : DBTestBase("/external_sst_file_test") {
+  ExternalSSTFileTest()
+      : DBTestBase("/external_sst_file_test", /*env_do_fsync=*/true) {
     sst_files_dir_ = dbname_ + "/sst_files/";
     DestroyAndRecreateExternalSSTFilesDir();
   }
diff --git a/db/import_column_family_test.cc b/db/import_column_family_test.cc
index e17895b46..37167034d 100644
--- a/db/import_column_family_test.cc
+++ b/db/import_column_family_test.cc
@@ -11,7 +11,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class ImportColumnFamilyTest : public DBTestBase {
  public:
-  ImportColumnFamilyTest() : DBTestBase("/import_column_family_test") {
+  ImportColumnFamilyTest()
+      : DBTestBase("/import_column_family_test", /*env_do_fsync=*/true) {
     sst_files_dir_ = dbname_ + "/sst_files/";
     DestroyAndRecreateExternalSSTFilesDir();
     export_files_dir_ = test::PerThreadDBPath(env_, "export");
diff --git a/db/listener_test.cc b/db/listener_test.cc
index de5eb58c6..2845f778b 100644
--- a/db/listener_test.cc
+++ b/db/listener_test.cc
@@ -41,7 +41,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class EventListenerTest : public DBTestBase {
  public:
-  EventListenerTest() : DBTestBase("/listener_test") {}
+  EventListenerTest() : DBTestBase("/listener_test", /*env_do_fsync=*/true) {}
 
   static std::string BlobStr(uint64_t blob_file_number, uint64_t offset,
                              uint64_t size) {
diff --git a/db/obsolete_files_test.cc b/db/obsolete_files_test.cc
index 42269a56c..98d98eae2 100644
--- a/db/obsolete_files_test.cc
+++ b/db/obsolete_files_test.cc
@@ -38,7 +38,8 @@ namespace ROCKSDB_NAMESPACE {
 class ObsoleteFilesTest : public DBTestBase {
  public:
   ObsoleteFilesTest()
-      : DBTestBase("/obsolete_files_test"), wal_dir_(dbname_ + "/wal_files") {}
+      : DBTestBase("/obsolete_files_test", /*env_do_fsync=*/true),
+        wal_dir_(dbname_ + "/wal_files") {}
 
   void AddKeys(int numkeys, int startkey) {
     WriteOptions options;
diff --git a/db/repair_test.cc b/db/repair_test.cc
index ba2bae3d0..d1b8fc700 100644
--- a/db/repair_test.cc
+++ b/db/repair_test.cc
@@ -22,7 +22,7 @@ namespace ROCKSDB_NAMESPACE {
 #ifndef ROCKSDB_LITE
 class RepairTest : public DBTestBase {
  public:
-  RepairTest() : DBTestBase("/repair_test") {}
+  RepairTest() : DBTestBase("/repair_test", /*env_do_fsync=*/true) {}
 
   std::string GetFirstSstPath() {
     uint64_t manifest_size;
diff --git a/monitoring/stats_history_test.cc b/monitoring/stats_history_test.cc
index 843e7d65d..ffa1f5e28 100644
--- a/monitoring/stats_history_test.cc
+++ b/monitoring/stats_history_test.cc
@@ -28,7 +28,8 @@ namespace ROCKSDB_NAMESPACE {
 
 class StatsHistoryTest : public DBTestBase {
  public:
-  StatsHistoryTest() : DBTestBase("/stats_history_test") {}
+  StatsHistoryTest()
+      : DBTestBase("/stats_history_test", /*env_do_fsync=*/true) {}
 };
 #ifndef ROCKSDB_LITE
 
diff --git a/utilities/option_change_migration/option_change_migration_test.cc b/utilities/option_change_migration/option_change_migration_test.cc
index 5bc883ff7..8fb9f1296 100644
--- a/utilities/option_change_migration/option_change_migration_test.cc
+++ b/utilities/option_change_migration/option_change_migration_test.cc
@@ -19,7 +19,7 @@ class DBOptionChangeMigrationTests
           std::tuple<int, int, bool, int, int, bool>> {
  public:
   DBOptionChangeMigrationTests()
-      : DBTestBase("/db_option_change_migration_test") {
+      : DBTestBase("/db_option_change_migration_test", /*env_do_fsync=*/true) {
     level1_ = std::get<0>(GetParam());
     compaction_style1_ = std::get<1>(GetParam());
     is_dynamic1_ = std::get<2>(GetParam());
@@ -350,7 +350,8 @@ INSTANTIATE_TEST_CASE_P(
 class DBOptionChangeMigrationTest : public DBTestBase {
  public:
   DBOptionChangeMigrationTest()
-      : DBTestBase("/db_option_change_migration_test2") {}
+      : DBTestBase("/db_option_change_migration_test2", /*env_do_fsync=*/true) {
+  }
 };
 
 TEST_F(DBOptionChangeMigrationTest, CompactedSrcToUniversal) {
diff --git a/utilities/persistent_cache/persistent_cache_test.cc b/utilities/persistent_cache/persistent_cache_test.cc
index 92b39307d..52fb66af5 100644
--- a/utilities/persistent_cache/persistent_cache_test.cc
+++ b/utilities/persistent_cache/persistent_cache_test.cc
@@ -295,7 +295,8 @@ TEST_F(PersistentCacheTierTest, FactoryTest) {
   }
 }
 
-PersistentCacheDBTest::PersistentCacheDBTest() : DBTestBase("/cache_test") {
+PersistentCacheDBTest::PersistentCacheDBTest()
+    : DBTestBase("/cache_test", /*env_do_fsync=*/true) {
 #ifdef OS_LINUX
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
diff --git a/utilities/simulator_cache/sim_cache_test.cc b/utilities/simulator_cache/sim_cache_test.cc
index 996ea90f6..ac2e24867 100644
--- a/utilities/simulator_cache/sim_cache_test.cc
+++ b/utilities/simulator_cache/sim_cache_test.cc
@@ -21,7 +21,7 @@ class SimCacheTest : public DBTestBase {
   const size_t kNumBlocks = 5;
   const size_t kValueSize = 1000;
 
-  SimCacheTest() : DBTestBase("/sim_cache_test") {}
+  SimCacheTest() : DBTestBase("/sim_cache_test", /*env_do_fsync=*/true) {}
 
   BlockBasedTableOptions GetTableOptions() {
     BlockBasedTableOptions table_options;