New build HDD LED never illuminates

[bart2000]

I recently set up an X12SPO-NTF running TrueNAS CORE. Everything seems to work except the HDD LED never blinks. I tried a LED from a different case but that did not help. I also tested the polarity and made sure that was correct.

I am running four SSDs. Two Intel P1600X 118GB M.2 boot drives and two Samsung PM9a3 7.68TB U.2 data drives.

I am not sure what is going on. I expect the HDD LED to sometimes illuminate do you think I have a bad motherboard? This is the first time I have used TrueNAS.

 

[jgreco]

Put it on a scope. I'll bet it's just blinking faster than you can see. Don't expect any blinking for the U.2 drives as those aren't driven by a controller, so there's nothing there to indicate any sort of activity.

 

[bart2000]

Put it on a scope. I'll bet it's just blinking faster than you can see. Don't expect any blinking for the U.2 drives as those aren't driven by a controller, so there's nothing there to indicate any sort of activity.

I tested up to 120hz no flashing. The X12SPO-NTF supports up to 10 U.2 drives via direct connect SlimSAS and that is what I am using.

 

[bart2000]

I tested up to 120hz no flashing. The X12SPO-NTF supports up to 10 U.2 drives via direct connect SlimSAS and that is what I am using.

ooops 240hz

 

[jgreco]

Try a conventional SATA HDD. What I'm thinking is that your typical SSD may be responding so fast you never see the light. 240HZ is nothing compared to the transactions per second these things can drive. I have seen various drives where the activity LED is barely visible even under heavy load; some drives like the Intel 535 actually implement a blinker circuit to blink the activity signal when stuff is going on. This of course only works when you have an individual LED for the drive (this is arranged through pin 11, staggered spinup and/or activity indicator). Your problem is that your signal is not being generated by the drive, but rather by the motherboard SATA controller, which may be flinging traffic (LED on) and receiving a response (LED off) so quickly that it never lights. In the same way that a PWM circuit can fade an LED to appear almost extinguished at a few percent on, you may simply be unable to see the activity.

 

[bart2000]

Try a conventional SATA HDD. What I'm thinking is that your typical SSD may be responding so fast you never see the light. 240HZ is nothing compared to the transactions per second these things can drive. I have seen various drives where the activity LED is barely visible even under heavy load; some drives like the Intel 535 actually implement a blinker circuit to blink the activity signal when stuff is going on. This of course only works when you have an individual LED for the drive (this is arranged through pin 11, staggered spinup and/or activity indicator). Your problem is that your signal is not being generated by the drive, but rather by the motherboard SATA controller, which may be flinging traffic (LED on) and receiving a response (LED off) so quickly that it never lights. In the same way that a PWM circuit can fade an LED to appear almost extinguished at a few percent on, you may simply be unable to see the activity.

With a SATA SSD it does blink. I am surprised that this board does not have the correct circuitry for the M.2 drives to blink correctly that tech has been on consumer boards for many years. I will contact Supermicro support to verify that this is expected behavior.

 

[jgreco]

With a SATA SSD it does blink. I am surprised that this board does not have the correct circuitry for the M.2 drives to blink correctly that tech has been on consumer boards for many years. I will contact Supermicro support to verify that this is expected behavior.

I can save you some time. You said Intel P1600X but I didn't bother looking to see what that was. Those are NVMe drives.

M.2 key M (SATA) puts DAS on pin 10. Even five years ago, many SATA M.2 didn't bother to drive this pin, because it was relatively unexpected to be used for anything. Some of us like to stick gumsticks into 2.5" adapters such as Sabrent's, but the LED behavior is unpredictable making backplane LED indication annoyingly inconsistent.

NVMe drives are even less likely to signal this.

Worse, the drive activity header on a Supermicro mainboard is very unlikely to "collect" these various signals and run them through an OR gate to generate a summary activity LED. It could be done, but typically they haven't done it for stuff like HBA HDD ports etc. It is typically just the activity signal from the SATA controller.

 

[bart2000]

That is totally correct and what Supermicro support told me as well.