Screeching sound on disk IO

[entith]

Hello,

I have recently gotten a Dell C2100 along with a PERC H310 that I flashed into IT mode. I have been able to get everything running with no issues so far.

My only problem is whenever there is disk IO, the system starts makes what I can best describe as an electronic screeching sound. I have never heard anything like this before, it does not sound like disk thrashing or anything. I guess it sort of sounds like an old dial-up modem, but generally higher pitched and somewhat more "subtle" (if that makes sense). I can try to get a recording uploaded if that'll help.

This seems to be coming from the area of the drive trays, but I have never heard drives make this kind of noise. This happens with two completely different (different age, model, brand, size, etc.) sets of drives. My best guess is its the backplane, but this is my first foray into server hardware and don't know if that is completely ridiculous.

I have tried searching online and on these forums, but haven't found anything closely related. I'm kind of at a loss as to how to even search for something like this.

Would greatly appreciate any insight anyone could offer. Thanks!

 

[nightshade00013]

A whine or screeching sound would be capacitor wine as my best guess. First thought would be a PSU that is starting to go bad, the caps will whine more when there is more power draw which can happen when drives are active.

But make sure the drives are having smart tests done and start going through them to check them out. If a drive is making the sound I highly doubt it is functioning correctly.

 

[entith]

Thanks for the suggestion! In all these years of working with computers, I somehow never heard of capacitor/coil whine. Looked up some Youtube videos, and that does seem to be what I am hearing.

I don't think its my power supplies, the sound physically doesn't seem to come from them, and persists whether I have either PSU or both plugged in.

Is it possible it is something on the backplane causing the whine?


Edit:
Something odd I just discovered. I have 2 sets of drives, each set configured in a separate pool/volume. If I copy data between the volumes, I get no whine, only normal HDD sounds.

Edit2:
At first I thought maybe this had to do with the speed, since the local transfer was much faster (not bottlenecked by the network), but if I threw enough simultaneous copies at it to bring total speed down below gigabit, still no whine.

I also tried copying to/from the USB drive FreeNAS is running off of (incase copying between drives somehow optimized/bypassed whatever was causing the whine), but still no whine.

So the whine only seems to happen when moving data via the network. I connected via SSH and used wget to download a file directly to one of my volumes and to the USB drive. Both instances caused whine.

The C2100 has two network ports, tried both and whine still happens.

I tried listening very closely again to see if I could pinpoint where the sound is coming from. I'm not sure why I was so confident it wasn't coming from the PSUs earlier, but now it seems to be coming from them. It is hard to pinpoint though.

Why would network activity cause a whine in the PSUs?

 

[nightshade00013]

Easiest way to pinpoint is to not use them. Assuming this is a case with redundant psu you would have to grab a different psu and connect it up and see if things persist. Since there is a redundancy in the psu's there is also a board they interconnect with that could have an issue. If it's only the network maybe a cap or choke on the MoBo but generally the PSU is the culprit from what I have always dealt with.