DNS-323 fan regularly starts and stops

[Thomas]

Hi,

after switch from D-Link firmware (with ffp), I recognize that the fan regularly starts/stops on disk "idle". It is a disturbing noise. Changes to temp limits didn't help. Does anyone got an idea what to check next?

Thomas

[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
40500
2908
37
[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
40500
2908
37
[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
40500
0
37
[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
41000
3536
37
[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
40500
2296
37
[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
41000
3052
37

[João Cardoso]

On Thursday, November 20, 2014 10:37:33 PM UTC, Thomas wrote:

Hi,

after switch from D-Link firmware (with ffp), I recognize that the fan regularly starts/stops on disk "idle". It is a disturbing noise. Changes to temp limits didn't help.

So you have a DNS-323-rev-B1, where the fan speed can be continuously adjusted between 2000/6000 RPM/S, and where the actual fan speed can be read back (as it happens on my own 323-B1 box)

Have you applied fix 008-lo_temp_sysctrl_webUI? (System->Utilities) 

# fix "sysctrl service UI doesn't display correct low temp value" 

# https://groups.google.com/forum/#!topic/alt-f/vLLzh194AkE

The log shows:

sysctrl: args.fan_off_temp=38

 

So the fan will turn on/off around this temperature (plus/minus 1ºC hysteresis). If you set it to 35ºC (after applying the webUI fix), that could help.

You might want to verify if the configuration if OK, see /etc/sysctrl.conf. 

The indicated system temperature is around 41ºC, higher than 38, does it oscillates around 38ºC?

It might be that the controller (sysctrl) tries to set it to a lower value than 2000RPM/S, and the fan will stop by itself, without being told to do it.

Or it might happen that your particular fan just stops at a higher RPM, say, 2200RPM/S... 

The exact situation has to be diagnosed (ah, found it, look bellow)

You can examine the System Log (System->Utilities, Logs) and filter (page bottom) with 'fan' to see just the fan/temperature changes (or logread | grep fan)

Does anyone got an idea what to check next?

Thomas

[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
40500
2908
37
[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
40500
2908
37
[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
40500
0
37

ah, pwm=37, meaning no fan off, yet the fan is stopped.

[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
41000
3536
37
[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
40500
2296
37

Here the fan is turning, with the same pwm.

[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1
41000
3052
37

You have several (read) fan speeds for the same (output) pwm.

 Your fan is  defective or jammed.

[Added:]

you can try it for yourself, stop syctrl, then set pwm as you which, and read back the actual fan speed:

rcsysctrl stop

echo 100 > /tmp/sys/pwm1 # non-linear relation-ship between pwm and fan speed
cat /tmp/sys/fan1_input
echo 120 > /tmp/sys/pwm1
cat /tmp/sys/fan1_input

when you start sysctrl ( using 'rcsysctrl start') it will override your settings. Notice that sysctrl controls more than just the fan, turn it off only for diagnose purposes.

 

[João Cardoso]

On Friday, November 21, 2014 12:44:32 AM UTC, João Cardoso wrote:

(...)

 

 Your fan is  defective or jammed.

you can try it for yourself, stop syctrl, then set pwm as you which, and read back the actual fan speed:

rcsysctrl stop

echo 100 > /tmp/sys/pwm1 # non-linear relationship between pwm and fan speed

cat /tmp/sys/fan1_input
echo 120 > /tmp/sys/pwm1
cat /tmp/sys/fan1_input

when you start sysctrl ( using 'rcsysctrl start') it will override your settings. Notice that sysctrl controls more than just the fan, turn it off only for diagnose purposes.

 

For completion, here is the actual pwm (Pulse Width Modulation) - fan speed relationship on my DNS-323-rev-B1, made some 4 years ago:

pwd=5 fan=1958

pwd=10 fan=1998

pwd=15 fan=2056

pwd=20 fan=2082

pwd=25 fan=2137

pwd=30 fan=2184

pwd=35 fan=2224

pwd=40 fan=2286

pwd=45 fan=2329

pwd=50 fan=2397

pwd=55 fan=2457

pwd=60 fan=2495

pwd=65 fan=2600

pwd=70 fan=2642

pwd=75 fan=2715

pwd=80 fan=2792

pwd=85 fan=2891

pwd=90 fan=2978

pwd=95 fan=3052

pwd=100 fan=3171

pwd=105 fan=3255

pwd=110 fan=3366

pwd=115 fan=3485

pwd=120 fan=3614

pwd=125 fan=3780

pwd=130 fan=3932

pwd=135 fan=4096

pwd=140 fan=4237

pwd=145 fan=4551

pwd=150 fan=4593

pwd=155 fan=4915

pwd=160 fan=5228

pwd=165 fan=5585

pwd=170 fan=5851

pwd=175 fan=5649

pwd=180 fan=6467 

The code uses the following equations to convert fan to rpm and vice-versa for the 323-rev-A1/B1 boards:

 * fan = 0.00111642 * x^3 - 0.148356 * x^2 + 16.3374 * x + 1839.55

 * x = pwm (5..180)

 *

 * pwm = 2.66029e-9 * x^3 - 4.28952e-5 * x^2 + 0.244737 * x - 328.233

 * x = fan (1900...6500)

 

What a preciosity! (or shall I call it "fastidiousness"?)

[Thomas]

Hi,

sorry for my late response and thank you for your great explanation. I have cleaned my fan but there were still problems.

After hdd replacement I haven't found any problems right now, but the temperature is higher than before.

[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1

41500
2730
74

[root@storage]# cat /sys/class/hwmon/hwmon1/device/temp1_input /sys/class/hwmon/hwmon0/device/fan1_input /sys/class/hwmon/hwmon0/device/pwm1

42000
2761
78

[root@storage]# logread | grep fan
Dec 31 18:55:13 storage daemon.info sysctrl: args.lo_fan=2000
Dec 31 18:55:13 storage daemon.info sysctrl: args.hi_fan=5000
Dec 31 18:55:13 storage daemon.info sysctrl: args.fan_off_temp=38
Dec 31 18:55:13 storage daemon.info sysctrl: args.max_fan_speed=6000
Dec 31 18:55:45 storage daemon.info sysctrl: temp=39.3     fan=0
Dec 31 19:04:47 storage daemon.info sysctrl: temp=39.6     fan=0
Dec 31 19:09:49 storage daemon.info sysctrl: temp=40.1     fan=2495
Dec 31 19:10:19 storage daemon.info sysctrl: temp=40.3     fan=2275
Dec 31 19:21:52 storage daemon.info sysctrl: temp=40.6     fan=2374
Dec 31 19:32:25 storage daemon.info sysctrl: temp=41.1     fan=2457
Dec 31 19:32:55 storage daemon.info sysctrl: temp=41.3     fan=2546
Dec 31 19:55:00 storage daemon.info sysctrl: temp=41.6     fan=2628
Dec 31 20:47:17 storage daemon.info sysctrl: temp=42.1     fan=2761
Dec 31 20:49:47 storage daemon.info sysctrl: temp=42.3     fan=2824
Jan  1 12:59:58 storage daemon.info sysctrl: temp=41.9     fan=2824
Jan  1 13:32:11 storage daemon.info sysctrl: temp=42.2     fan=2776
Jan  1 15:41:14 storage daemon.info sysctrl: temp=41.8     fan=2824
Jan  1 17:45:40 storage daemon.info sysctrl: temp=42.2     fan=2776
Jan  1 18:28:14 storage daemon.info sysctrl: temp=41.8     fan=2808

I will study this and if there are still problems I will buy a new "ad0405hb-g73" fan.

Regards
Thomas

[João Cardoso]

You can just make the fan turn faster, so it will exhaust more heat from the box.

You can, e.g. increase the low fan speed from 2000 to 2500 or 3000 RPM, or lower the High Temp from 50 to 45ºC in Services->System->sysctrl, Configure. The defaults are:

Low Temp. 40°C Low Fan Speed 2000RPM

High Temp. 50°C High Fan Speed 6000RPM

Regards
Thomas