diff --git a/config/config.md b/config/config.md
index caa7dbf64aee..765fd8dd87b4 100644
--- a/config/config.md
+++ b/config/config.md
@@ -61,7 +61,7 @@
 | `wal` | -- | -- | The WAL options. |
 | `wal.provider` | String | `raft_engine` | The provider of the WAL.<br/>- `raft_engine`: the wal is stored in the local file system by raft-engine.<br/>- `kafka`: it's remote wal that data is stored in Kafka. |
 | `wal.dir` | String | Unset | The directory to store the WAL files.<br/>**It's only used when the provider is `raft_engine`**. |
-| `wal.file_size` | String | `256MB` | The size of the WAL segment file.<br/>**It's only used when the provider is `raft_engine`**. |
+| `wal.file_size` | String | `128MB` | The size of the WAL segment file.<br/>**It's only used when the provider is `raft_engine`**. |
 | `wal.purge_threshold` | String | `1GB` | The threshold of the WAL size to trigger a flush.<br/>**It's only used when the provider is `raft_engine`**. |
 | `wal.purge_interval` | String | `1m` | The interval to trigger a flush.<br/>**It's only used when the provider is `raft_engine`**. |
 | `wal.read_batch_size` | Integer | `128` | The read batch size.<br/>**It's only used when the provider is `raft_engine`**. |
@@ -399,7 +399,7 @@
 | `wal` | -- | -- | The WAL options. |
 | `wal.provider` | String | `raft_engine` | The provider of the WAL.<br/>- `raft_engine`: the wal is stored in the local file system by raft-engine.<br/>- `kafka`: it's remote wal that data is stored in Kafka. |
 | `wal.dir` | String | Unset | The directory to store the WAL files.<br/>**It's only used when the provider is `raft_engine`**. |
-| `wal.file_size` | String | `256MB` | The size of the WAL segment file.<br/>**It's only used when the provider is `raft_engine`**. |
+| `wal.file_size` | String | `128MB` | The size of the WAL segment file.<br/>**It's only used when the provider is `raft_engine`**. |
 | `wal.purge_threshold` | String | `1GB` | The threshold of the WAL size to trigger a flush.<br/>**It's only used when the provider is `raft_engine`**. |
 | `wal.purge_interval` | String | `1m` | The interval to trigger a flush.<br/>**It's only used when the provider is `raft_engine`**. |
 | `wal.read_batch_size` | Integer | `128` | The read batch size.<br/>**It's only used when the provider is `raft_engine`**. |
diff --git a/config/datanode.example.toml b/config/datanode.example.toml
index 5e4ddabb53dd..088980218891 100644
--- a/config/datanode.example.toml
+++ b/config/datanode.example.toml
@@ -142,7 +142,7 @@ dir = "/tmp/greptimedb/wal"
 
 ## The size of the WAL segment file.
 ## **It's only used when the provider is `raft_engine`**.
-file_size = "256MB"
+file_size = "128MB"
 
 ## The threshold of the WAL size to trigger a flush.
 ## **It's only used when the provider is `raft_engine`**.
diff --git a/config/standalone.example.toml b/config/standalone.example.toml
index 137a73c55e97..480286349427 100644
--- a/config/standalone.example.toml
+++ b/config/standalone.example.toml
@@ -147,7 +147,7 @@ dir = "/tmp/greptimedb/wal"
 
 ## The size of the WAL segment file.
 ## **It's only used when the provider is `raft_engine`**.
-file_size = "256MB"
+file_size = "128MB"
 
 ## The threshold of the WAL size to trigger a flush.
 ## **It's only used when the provider is `raft_engine`**.
diff --git a/src/common/wal/src/config/raft_engine.rs b/src/common/wal/src/config/raft_engine.rs
index 15adf195c4b2..cfefd0c758b7 100644
--- a/src/common/wal/src/config/raft_engine.rs
+++ b/src/common/wal/src/config/raft_engine.rs
@@ -49,7 +49,7 @@ impl Default for RaftEngineConfig {
     fn default() -> Self {
         Self {
             dir: None,
-            file_size: ReadableSize::mb(256),
+            file_size: ReadableSize::mb(128),
             purge_threshold: ReadableSize::gb(1),
             purge_interval: Duration::from_secs(60),
             read_batch_size: 128,
diff --git a/tests-integration/tests/http.rs b/tests-integration/tests/http.rs
index 42b5c441f8fb..056cdc5481d2 100644
--- a/tests-integration/tests/http.rs
+++ b/tests-integration/tests/http.rs
@@ -881,7 +881,7 @@ with_metric_engine = true
 
 [wal]
 provider = "raft_engine"
-file_size = "256MiB"
+file_size = "128MiB"
 purge_threshold = "1GiB"
 purge_interval = "1m"
 read_batch_size = 128