Updated FAQ (markdown)

FAQ.md

@@ -151,6 +151,26 @@ https://github.com/rustdesk/rustdesk/wiki/How-does-RustDesk-work%3F
 
 ![image](https://github.com/rustdesk/rustdesk/assets/71636191/ce224ff8-16cf-4d7e-9277-c106c08a927a)
 
+# log file rotation
+
+> I assume that if the logs become very large, they could consume a significant amount of disk space. In general, how is this typically handled?
+
+From the code, it keeps 31 log files only, so it won't fill up your disk.
+
+https://github.com/rustdesk/hbb_common/blob/900077a2c2651336317f8094ea44074c48acd2a4/src/lib.rs#L407
+
+```
+                     .rotate(
+
+                         Criterion::Age(Age::Day),
+
+                         Naming::Timestamps,
+
+                         Cleanup::KeepLogFiles(31),
+
+                     )
+```
+
 # logs of `hbbs` and `hbbr` (RustDesk Server)
 
 If you install with `install.sh` or deb, the logs files are `hbbr.log` and `hbbs.log` under `/var/log/rustdesk-server/`. 
@@ -1786,3 +1806,4 @@ https://github.com/rustdesk/rustdesk/discussions/1258
 https://github.com/rustdesk/rustdesk-server-pro/issues/833
 
 
+