add-tikv-config: add max-days and max-backups

en/configure-a-tidb-cluster.md

@@ -408,13 +408,17 @@ spec:
       [storage]
         [storage.block-cache]
           capacity = "16GB"
+      [log.file]
+        max-days = 30
+        max-backups = 30
 ```
 
 For all the configurable parameters of TiKV, refer to [TiKV Configuration File](https://docs.pingcap.com/tidb/stable/tikv-configuration-file).
 
 > **Note:**
 >
-> If you deploy your TiDB cluster using CR, make sure that `Config: {}` is set, no matter you want to modify `config` or not. Otherwise, TiKV components might not be started successfully. This step is meant to be compatible with `Helm` deployment.
+> - If you deploy your TiDB cluster using CR, make sure that `Config: {}` is set, no matter you want to modify `config` or not. Otherwise, TiKV components might not be started successfully. This step is meant to be compatible with `Helm` deployment.
+> - TiKV RocksDB logs are stored in the `/var/lib/tikv` data directory. It is recommended that you configure `max-days` and `max-backups` to automatically clean log files.
 
 #### Configure PD parameters
 

zh/configure-a-tidb-cluster.md

@@ -402,13 +402,17 @@ spec:
       [storage]
         [storage.block-cache]
           capacity = "16GB"
+      [log.file]
+        max-days = 30
+        max-backups = 30
 ```
 
 获取所有可以配置的 TiKV 配置参数，请参考 [TiKV 配置文档](https://docs.pingcap.com/zh/tidb/stable/tikv-configuration-file)
 
 > **注意：**
 >
-> 为了兼容 `helm` 部署，如果你是通过 CR 文件部署 TiDB 集群，即使你不设置 Config 配置，也需要保证 `Config: {}` 的设置，从而避免 TiKV 组件无法正常启动。
+> - 为了兼容 `helm` 部署，如果你是通过 CR 文件部署 TiDB 集群，即使你不设置 Config 配置，也需要保证 `Config: {}` 的设置，从而避免 TiKV 组件无法正常启动。
+> - TiKV 的 RocksDB 日志默认存储在 `/var/lib/tikv` 数据目录，建议配置 `max-days` 和 `max-backups` 来自动清理日志文件。
 
 #### 配置 PD 配置参数