UNRAID: After uploading approximately 500~650MB, the speed drops to mere KB/s. Various troubleshooting methods have been attempted, but the issue persists consistently. The root cause remains unclear.

Has anyone encountered similar issues? Guidance would be greatly appreciated.

bnas-diagnostics-20250601-1037.zip

Is this writing to the array, pool, or both?

1 hour ago, JorgeB said:

Is this writing to the array, pool, or both?

array.

Once the speed drops to mere KB/s, it remains persistently slow. Normal high-speed upload capability only resumes after a period of time, allowing another 500~650MB upload before again reverting to KB/s speeds.

If it's just with the array, it suggests a problem with one of the disks, try writing to a different disk, if the same, try temporarily removing parity.

15 hours ago, JorgeB said:

If it's just with the array, it suggests a problem with one of the disks, try writing to a different disk, if the same, try temporarily removing parity.

Thank you for the suggestions.

I've also tested uploading to other pools - including those made of different HDD configurations and SSD pools - and observed the same behavior.

The issue likely isn't specific to the array.

5 hours ago, ByronD said:

I've also tested uploading to other pools

Then why did you reply the array was the problem?

22 hours ago, ByronD said:

  On 6/1/2025 at 9:12 AM, JorgeB said:

Is this writing to the array, pool, or both?

array.

2 hours ago, JorgeB said:

Then why did you reply the array was the problem?

Apologies for any confusion caused.

To clarify: my earlier tests were conducted on directories within the array, but this wasn't meant to imply the array was the root cause.

Following your suggestion, I've now tested pools and confirmed the same issue occurs there.

Post a screenshot from the Windows explorer transfer graph with large files, and also the diags saved during the transfer.

54 minutes ago, JorgeB said:

Post a screenshot from the Windows explorer transfer graph with large files, and also the diags saved during the transfer.

Thank you for the suggestions. To address your requests:

1. Network Environment:
   The NAS isn't on my local network - it's remotely accessed through a reverse proxy at a separate physical location.

2. Consistent Reproduction Paths:
   The slowdown occurs identically when uploading via:

   • UNRAID's native Simple File Manager

   • Cloud applications (e.g. kodbox Tunnel) running in Docker containers

3. Diagnostics Clarification Needed:
   While I can reproduce the issue on demand, could you advise how to properly capture diagnostics during active transfers?

19 minutes ago, ByronD said:

it's remotely accessed through a reverse proxy at a separate physical location.

Can't help with that, I assumed it was local install, there are many other factors a play in that case, and I'm not familiar with those.