From c658f871a58f16be0b0bf228c46c40c120048335 Mon Sep 17 00:00:00 2001
From: Evgeniy Khramtsov <ekhramtsov@process-one.net>
Date: Mon, 18 Dec 2017 12:30:10 +0300
Subject: [PATCH] Log a warning when a disk is almost full

---
 src/ejabberd_system_monitor.erl | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/ejabberd_system_monitor.erl b/src/ejabberd_system_monitor.erl
index 2694f1ab0..926cea552 100644
--- a/src/ejabberd_system_monitor.erl
+++ b/src/ejabberd_system_monitor.erl
@@ -63,7 +63,6 @@ start() ->
     gen_event:swap_handler(alarm_handler, {alarm_handler, swap}, {?MODULE, []}),
     application:load(os_mon),
     application:set_env(os_mon, start_cpu_sup, false),
-    application:set_env(os_mon, start_disksup, false),
     application:set_env(os_mon, start_os_sup, false),
     application:set_env(os_mon, start_memsup, true),
     ejabberd:start_app(os_mon).
@@ -102,6 +101,12 @@ handle_event({set_alarm, {process_memory_high_watermark, Pid}}, State) ->
     end;
 handle_event({clear_alarm, process_memory_high_watermark}, State) ->
     {ok, State};
+handle_event({set_alarm, {{disk_almost_full, MountPoint}, _}}, State) ->
+    error_logger:warning_msg("Disk is almost full on ~p", [MountPoint]),
+    {ok, State};
+handle_event({clear_alarm, {disk_almost_full, MountPoint}}, State) ->
+    error_logger:info_msg("Disk usage is back to normal on ~p", [MountPoint]),
+    {ok, State};
 handle_event(Event, State) ->
     error_logger:warning_msg("unexpected event: ~p", [Event]),
     {ok, State}.