Couple of days ago I got my brand new Synology DS224+ disk station, which was meant to replace my current (and old) Synology DS213j system.

My old DS213j system has served me well for the past ten years, and I have been pretty happy with it. Synology also did an awesome job by providing security updates for all these years to old devices such as the DS213j I have. However, it was time for an upgrade.

After some researching I’ve decided to grab the DS224+, which is a great improvement over my current DS213j. It runs with with 4 cores Intel Celeron J4125 CPU and comes with 2GB of memory, and you have the option to upgrade the memory to 6GB in total. And it also has dual-port NICs. Sweet.

For comparison my DS213j runs with a single core Marvell Kirkwood 1.2GHz and has 512MB of memory. And it has a single NIC.

Like I’ve mentioned – my DS213j has served me well for the past years, and I still keep it around. One of the things that I really like about the DS213j is how quiet it actually is.

So, after getting the DS224+ and installing latest DSM 7.2.2 one thing immediately caught my attention – the noise coming from the fan. And that noise was simply annoying and clicking. I’ve recorded a video of the fan noise, coming out of my brand new DS224+, which you can also listen to.

The first I did was to make sure that the fan is configured in Quiet Mode and to my surprise – that was already the case.

Unfortunately, it turned out that I’m not the only one having such issues with the DS224+. A number of people have already reported similar issues, which you can find in the links below.

• ds224+ fan noise is driving me crazy
• Ds224+ disk noise and slowness?
• DS224+ fan noise at low speed
• DS224+ constant “clicking” sound that doesn’t seem related to the drives

Interestingly, the only way you can make that annoying noise disappear is if you simply switch from Quiet Mode to Full-speed mode in the Fan Speed Mode settings. However, that’s not what I really want to do.

The DS213j and DS224+ while being different in terms of CPUs, architecture, amount of memory, etc., are identical in one thing – and that is the fan they run with.

The Synology Spare Parts page confirms that as well.

Back in the day I had to replace the fan of my old DS213j and I’ve used a Noctua NF-A9 FLX / 3 pins, which to this day is still running. So, I thought about doing the same with my DS224+ as well – replace the stock fan with a NF-A9 FLX 3-pin fan, however some people have reported issues when using this fan in particular with DSM 7.2.x (check the links above for more details).

Another Noctua fan, for which people have reported good results in replacing their stock fan is the Noctua NF-B9-redux-1600, 92 x 92 x 25 mm / 3 pins, however I didn’t have a spare one I could use immediately, and I had to order one.

And while waiting for the NF-B9-redux-1600 to arrive I had to keep listening to that annoying, clicking sound coming from the DS224+ stock fan. Needless to say, I had time to tinker with the new DS224+ and see what can be done to fix this.

After some researching and testing various things I eventually found out about /usr/syno/etc.defaults/scemd.xml, which is the configuration for the fan curve. This file is parsed by the scemd service and is used to configure various disk and CPU temperature thresholds, which when reached will configure the fan to run either at low and high speeds, so that the system can cool down.

Comparing this file on my DS224+ with the same file on my old DS213j showed some differences, which I expected anyways. However, having the exact same fan on both systems, I would at least expect that the fans behave the same (unless one of them is actually broken).

You can find the original scemd.xml files for DS213j and DS224+, which I’ve extracted from my systems here.

• DS213j scemd.xml
• DS224+ scemd.xml

Some time later I’ve also found a post from a folk at Reddit, who has provided details about how he/she fixed the same annoying noise by adjusting the fan curve profile in /usr/syno/etc.defaults/scemd.xml. You can find the post here.

I’ve tried the instructions he left and it actually made a difference on my DS224+, however there was still a minor low frequency noise coming out of that fan, which I was not happy with.

Then I’ve decided to simply adapt my existing DS213j config for DS224+. Turned out it was pretty simple, and I didn’t have to deal with any of the conversions from frequency (Hz) to RPM values.

A snippet of changes I did to my /usr/syno/etc.defaults/scemd.xml file are provided below.

        <fan_config period="20" threshold="6" type="DUAL_MODE_HIGH" hibernation_speed="UNKNOWN">
		<disk_temperature fan_speed="ULTRA_LOW"  action="NONE">0</disk_temperature>
		<disk_temperature fan_speed="VERY_LOW"   action="NONE">33</disk_temperature>
		<disk_temperature fan_speed="LOW"        action="NONE">41</disk_temperature>
		<disk_temperature fan_speed="VERY_HIGH"  action="NONE">47</disk_temperature>
		<disk_temperature fan_speed="ULTRA_HIGH" action="NONE">53</disk_temperature>
		<disk_temperature fan_speed="ULTRA_HIGH" action="SHUTDOWN">61</disk_temperature>

		<cpu_temperature fan_speed="ULTRA_LOW"   action="NONE">0</cpu_temperature>
		<cpu_temperature fan_speed="LOW"         action="NONE">55</cpu_temperature>
		<cpu_temperature fan_speed="HIGH"        action="NONE">65</cpu_temperature>
		<cpu_temperature fan_speed="ULTRA_HIGH"  action="SHUTDOWN">95</cpu_temperature>
	</fan_config>
	<fan_config period="20" threshold="6" type="DUAL_MODE_LOW" hibernation_speed="UNKNOWN">
		<disk_temperature fan_speed="ULTRA_LOW"  action="NONE">0</disk_temperature>
		<disk_temperature fan_speed="VERY_LOW"   action="NONE">38</disk_temperature>
		<disk_temperature fan_speed="LOW"        action="NONE">46</disk_temperature>
		<disk_temperature fan_speed="HIGH"       action="NONE">52</disk_temperature>
		<disk_temperature fan_speed="VERY_HIGH"  action="NONE">55</disk_temperature>
		<disk_temperature fan_speed="ULTRA_HIGH" action="NONE">58</disk_temperature>
		<disk_temperature fan_speed="ULTRA_HIGH" action="SHUTDOWN">61</disk_temperature>

		<cpu_temperature fan_speed="ULTRA_LOW"   action="NONE">0</cpu_temperature>
		<cpu_temperature fan_speed="LOW"         action="NONE">55</cpu_temperature>
		<cpu_temperature fan_speed="HIGH"        action="NONE">65</cpu_temperature>
		<cpu_temperature fan_speed="ULTRA_HIGH"  action="SHUTDOWN">95</cpu_temperature>
	</fan_config>

You can also find the full updated scemd.xml file here.

Feel free to adjust the threshold temperatures for disk and CPU to other values, if needed.

After you make changes to the /usr/syno/etc.defaults/scemd.xml file make sure that you restart the scemd service.

sudo systemctl restart scemd

And with these changes made to scemd.xml the clicking noise coming from the DS224+ fan went away for me, so now I don’t even have to replace it.