Copying music library to NucleusOne internal storage fails (ref#YPPI6M)

Jim_Reinsma · January 19, 2026, 3:29pm

Hi! What’s not quite right with Roon?

· None of the above quite fits

None of the above quite fits

· None of these quite match

Tell us what's going on

· Hello, I have installed a 4Tb SSD in my new Nucleusone and formatted it correctly. Trying to copy my 2.5Tb music library has so far been unsuccessful. I have used and older macbook pro and a newer mac mini M1 copying over the network to the Nucleus internal storage has not worked. within minutes I will get an error and the process stops. The nucleus data drive as become un available at times and my till now trusted solution for copying large libraries by using TerraCopy has also failed.
copying the same library from mac to mac over the same network is no problem only copying to the InternalStorage drive fails. I have even purchased another brand (WD) SSD to be sure there is no problem there. When I plug in the same library on an NVME 4Tb drive via USB directly in the Nucleus it indexes everything immediately without fault.
I am running out of ideas here and any suggestions will be welcome! THX, Jim

Tell us about your home network

· I run an Omada SDN network where the Nucleus and the Mac are connected via GigaEthernet ports on a managed switch. I also have the Nucleus connected via USB to and Eversolo DMP-A10. without issues

alex_h · January 19, 2026, 4:11pm

@Jim_Reinsma,

Thanks for posting about this.

Could you please clarify how the disk is formatted? We recommend using exFAT.

Also, please make sure to stop Roon Server via the Web UI while copying, and turn it back on once you’re finished.

If the process fails again, could you please let us know exactly what error message you see and the specific time it happened.

Thanks.

Jim_Reinsma · January 19, 2026, 5:12pm

The Nucleus does not provide info on how it formats the internal ssd. It is also not selectable.

I will try again with server shut down.

Thx,
Jim

alex_h · January 20, 2026, 1:23pm

@Jim_Reinsma,

I was just able to review the diagnostics data from your device and can confirm that it is formatted as exFAT, as recommended.

In this case, we recommend copying the files while Roon Server is stopped.

Please let us know if that solves the problem.

Jim_Reinsma · January 20, 2026, 2:35pm

As I mentioned the formatting protocol is fixed, not user selectable. I could format the drive in ExFat on the Mac and copy the music files but the nucleus does not allow that unless there is another way to install the ROON OS.

Anyway, the problems persist even with the server halted. The network connection does not seem to be consistent and disconnect at times which crashes the copy process. When I do the same from Mac to Mac with the same drives it works without fault and a lot faster as well.
I will attach the error message screen shots.
In short: over my network I can copy the same data from the same source drive Mac to Mac and Mac to DMP-A10 but not to the nucleus. It feels like you have a networking bug in your OS.

alex_h · January 20, 2026, 3:18pm

@Jim_Reinsma, thanks for sharing the screenshots.

We would like to ask you to try the following steps to narrow down the cause:

Simplify the network: Please try to remove the switch from the connection chain and test again.
Safe Mode: If that doesn't help, please boot your Mac into [url=https://support.apple.com/en-us/116946]Safe Mode[/url] and try again on the simplified network.

Please let us know how this works for you.

Jim_Reinsma · January 20, 2026, 3:29pm

Here is another Idea: Could I connect the Nucleus directly to the Mac via usb or Ethernet and could I transfer data that way?

BlackJack · January 20, 2026, 5:32pm

No for USB, theoretically yes for Ethernet – but the setup can be a PITA and if you have to ask, you’re probably not up to it.

You can try and use the steps from the following article to resolve your MacOS issue:

Jim_Reinsma · January 20, 2026, 6:53pm

Thx @BlackJack
That is helpful. I found something else that seems to have fixed the problem. Mac has a spotlight search function that appears to index the whole system including shared drives. This frequently reindexes content and creates problems for filetransfer. Especially large transfers. After I disabled spotlight for the used drives as well as made sure that sharing rights included guests login I got it to work.

alex_h · January 21, 2026, 1:53pm

@Jim_Reinsma,

Thanks for sharing the solution.

We’ll make a note of this.

Thanks.

Jim_Reinsma · January 21, 2026, 2:09pm

I still had a couple of hiccups with error code 51 but now it became manageable. Also rebooted twice due to ROON server drive lost.
Nucleus and Mac is obviously not a great match.
All in all it’s running great now!

Thx for all the help and suggestions

system · January 22, 2026, 2:09pm

This topic was automatically closed 24 hours after the last reply. New replies are no longer allowed.