+ add "Limitations" section

Getting-Started.md

@@ -8,6 +8,7 @@ In order to start using AdGuard Home, you need to do a few things:
 4. [How to update](#update)
 5. [Configure your devices](#configure-devices)
 6. [Running without superuser (linux only)](#running-without-superuser)
+7. [Limitations](#limitations)
 
 <a id="installation"></a>
 ## Installation
@@ -171,4 +172,23 @@ dns:
 
 You can change port 53 to anything above 1024 to avoid requiring superuser privileges.
 
-If the file does not exist, create it in the same folder, type these two lines down and save.
+If the file does not exist, create it in the same folder, type these two lines down and save.
+
+
+<a id="limitations"></a>
+## Limitations
+
+### Doesn't work on some file systems
+
+Some file systems don't support `mmap()` system call that Statistics module requires (more details here: https://github.com/AdguardTeam/AdGuardHome/issues/1188).
+
+You can resolve this issue:
+
+* by supplying `--work-dir DIRECTORY` arguments to `AdGuardHome` binary.  This option will tell AGH to use another directory for all its files (by default it's set to `./data`).
+
+* or you can create symbolic links pointing to another file system that supports `mmap()` (e.g. tmpfs):
+
+  ```
+  ln -s <YOUR_AGH_PATH>/data/stats.db /tmp/stats.db
+  ln -s <YOUR_AGH_PATH>/data/sessions.db /tmp/sessions.db
+  ```