update tikv docs for titan fallback

experimental-features.md

@@ -38,7 +38,6 @@ Elastic scheduling feature. It enables the TiDB cluster to dynamically scale out
 
 ## Storage
 
-+ [Disable Titan](/storage-engine/titan-configuration.md#disable-titan-experimental) (Introduced in v4.0)
 + [Titan Level Merge](/storage-engine/titan-configuration.md#level-merge-experimental) (Introduced in v4.0)
 + Divide Regions are divided into buckets. [Buckets are used as the unit of concurrent query](/tune-region-performance.md#use-bucket-to-increase-concurrency) to improve the scan concurrency. (Introduced in v6.1.0)
 + TiKV introduces [API V2](/tikv-configuration-file.md#api-version-new-in-v610). (Introduced in v6.1.0)
@@ -49,7 +48,7 @@ Elastic scheduling feature. It enables the TiDB cluster to dynamically scale out
 + [Configure disk quota](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#configure-disk-quota-new-in-v620) for TiDB Lightning. (Introduced in v6.2.0)
 + [Continuous Data Validation in DM](/dm/dm-continuous-data-validation.md) (Introduced in v6.2.0)
 
-## 数据共享订阅
+## Data share subscription
 
 + [Cross-cluster RawKV replication](/tikv-configuration-file.md#api-version-new-in-v610) (Introduced in v6.2.0)
 

storage-engine/titan-configuration.md

@@ -45,7 +45,7 @@ If you want to speed up the writing process, compact data of the whole TiKV clus
 
 > **Note:**
 >
-> When Titan is disabled, RocksDB cannot read data that has been migrated to Titan. If Titan is incorrectly disabled on a TiKV instance with Titan already enabled (mistakenly set `rocksdb.titan.enabled` to `false`), TiKV will fail to start, and the `You have disabled titan when its data directory is not empty` error appears in the TiKV log. To correctly disabled Titan, see [Disable Titan](#disable-titan-experimental).
+> When Titan is disabled, RocksDB cannot read data that has been migrated to Titan. If Titan is incorrectly disabled on a TiKV instance with Titan already enabled (mistakenly set `rocksdb.titan.enabled` to `false`), TiKV will fail to start, and the `You have disabled titan when its data directory is not empty` error appears in the TiKV log. To correctly disabled Titan, see [Disable Titan](#disable-titan).
 
 ## Parameters
 
@@ -110,19 +110,38 @@ To adjust Titan-related parameters using TiUP, refer to [Modify the configuratio
     rate-bytes-per-sec = 0
     ```
 
-## Disable Titan (experimental)
+## Disable Titan
 
 To disable Titan, you can configure the `rocksdb.defaultcf.titan.blob-run-mode` option. The optional values for `blob-run-mode` are as follows:
 
 - When the option is set to `normal`, Titan performs read and write operations normally.
 - When the option is set to `read-only`, all newly written values are written into RocksDB, regardless of the value size.
 - When the option is set to `fallback`, all newly written values are written into RocksDB, regardless of the value size. Also, all compacted values stored in the Titan blob file are automatically moved back to RocksDB.
 
-To disable Titan, set `blob-run-mode = "fallback"` and perform a full compaction using tikv-ctl. After that, check the monitoring metrics, confirm that the blob file size decreases to `0`. Then you can set `rocksdb.titan.enabled` to `false` and restart TiKV.
+To fully disable Titan for all existing and future data, you can follow these steps:
 
-> **Warning:**
->
-> Disabling Titan is an experimental feature. It is **NOT** recommended to use it if not necessary.
++ First update the configuration of the TiKV nodes you wish to disable Titan. This can be done either with `tiup cluster edit-config` followed by `tiup cluster reload`, or manually updating the configuration file and restarting TiKV.
+
+    ```toml
+    [rocksdb.defaultcf.titan]
+    blob-run-mode = "fallback"
+    discardable-ratio = 1.0
+    ```
+
++ Then perform a full compaction using tikv-ctl. This process will consume large amount of I/O and CPU resources.
+
+    ```bash
+    tikv-ctl --pd <PD_ADDR> compact-cluster --bottommost force
+    ```
+
++ After the compaction is finished, you should wait for the "Blob file count" metrics under "TiKV-Details/Titan - kv" to decrease to `0`.
+
++ Finally, update the configuration of these TiKV nodes to disable Titan.
+
+    ```toml
+    [rocksdb.titan]
+    enabled = false
+    ```
 
 ## Level Merge (experimental)
 

tikv-configuration-file.md

@@ -482,8 +482,8 @@ Configuration items related to the I/O rate limiter.
 ### `mode`
 
 + Determines which types of I/O operations are counted and restrained below the `max-bytes-per-sec` threshold. Currently, only the write-only mode is supported.
-+ Optional value: `"write-only"`
-+ Default value: `"write-only"`
++ Optional values: `"read-only"`, `"write-only"`, `"all-io"`
++ Default value: `"all-io"`
 
 ## raftstore