Unable to write tags to files on NAS

Mac
1

Hi, thanks for any guidance, hopefully I’m not out of luck with this but I’ve just installed the trial mac version of this software because I have a massive use case I had hoped this would help me with.

However, Mp3tag can’t write tag to my files on my ReadyNAS. From searching the forums, it seems pretty identical to this thread which didn’t look like it was resolved: NAS Write failures

Writing tags works if I move the files to my machine but I need to add a UUID to every music file so that isn’t practical for ~500GB of files. Happy to troubleshoot and try stuff if it’s worth it. Thanks in advance for any assistance.

2

Sorry, should have added this extra info in my original post!

Main computer is running 10.15.7 Catalina, the NAS is a ReadyNAS running ReadyNASOS 6.10.10 on top of Debian v8 “jessie” which I know is ancient.

Pretty much all my tagging needs were taken care of by a macOS app called Squeed, which unfortunately is now abandonware. I’ve also tried Picard in the last couple of days, both had no issue with adding/deleting/amending tags on my NAS so I’m hoping this means it is solveable.

More info:

  • using Mp3tag 1.9.6 for macOS
  • have tried
    • drag & dropping folders
    • drag & dropping files
    • opening the folder from within Mp3tag
    • opening the file from within Mp3tag

Each time, when I attempt to run the action to add a UUID, the error is Cannot write tags to file “filename.flac” in folder “foldername”

3

Thank you for all the details. Looks like you already tried a lot!

BackLog is a tool that can gather logs already stored on your Mac that can give more detailed insights into what might be causing an issue.

You can set the process to Mp3tag and include all events not directly created by this binary. It's essentially a more user-friendly version of what Console.app does.

4

Thanks for your reply & suggestion.

This is the output when dragging and dropping a single file:

Summary

2025-08-28 20:57:01.926+0100 -- Mp3tag (Mp3tag) -- Found secure bookmark for file:///Volumes/Music/Singles%20:%20EPs/Deep%20House/Chris%20Gray%20and%20Malcolm%20Moore%20%E2%80%94%20(2010)%20Mysteries%20of%20the%20Ampalaya%20%E2%80%94%20%5BAMR-19R%5D/01%20Chris%20Gray%20-%20If%20They%20Could%20Tax%20Flamboyance.flac at file:///Volumes/Music/Singles%20:%20EPs/Deep%20House/Chris%20Gray%20and%20Malcolm%20Moore%20%E2%80%94%20(2010)%20Mysteries%20of%20the%20Ampalaya%20%E2%80%94%20%5BAMR-19R%5D/
2025-08-28 20:57:01.945+0100 -- Mp3tag (Mp3tag) -- Resolved secure bookmark to file:///Volumes/Music/Singles%20:%20EPs/Deep%20House/Chris%20Gray%20and%20Malcolm%20Moore%20%E2%80%94%20(2010)%20Mysteries%20of%20the%20Ampalaya%20%E2%80%94%20%5BAMR-19R%5D/
2025-08-28 20:57:06.721+0100 -- Mp3tag (Mp3tag) -- Found secure bookmark for file:///Volumes/Music/Singles%20:%20EPs/Deep%20House/Chris%20Gray%20and%20Malcolm%20Moore%20%E2%80%94%20(2010)%20Mysteries%20of%20the%20Ampalaya%20%E2%80%94%20%5BAMR-19R%5D/01%20Chris%20Gray%20-%20If%20They%20Could%20Tax%20Flamboyance.flac at file:///Volumes/Music/Singles%20:%20EPs/Deep%20House/Chris%20Gray%20and%20Malcolm%20Moore%20%E2%80%94%20(2010)%20Mysteries%20of%20the%20Ampalaya%20%E2%80%94%20%5BAMR-19R%5D/
2025-08-28 20:57:06.722+0100 -- Mp3tag (Mp3tag) -- Resolved secure bookmark to file:///Volumes/Music/Singles%20:%20EPs/Deep%20House/Chris%20Gray%20and%20Malcolm%20Moore%20%E2%80%94%20(2010)%20Mysteries%20of%20the%20Ampalaya%20%E2%80%94%20%5BAMR-19R%5D/
2025-08-28 20:57:06.739+0100 -- Mp3tag (Mp3tag) -- Error when requesting length of object: '9'.
2025-08-28 20:57:06.739+0100 -- Mp3tag (Mp3tag) -- Exception at reading FLAC metadata from '/Volumes/Music/Singles : EPs/Deep House/Chris Gray and Malcolm Moore — (2010) Mysteries of the Ampalaya — [AMR-19R]/01 Chris Gray - If They Could Tax Flamboyance.flac': Length of object is unknown.
2025-08-28 20:57:06.751+0100 -- Mp3tag (Mp3tag) -- Cannot write tags to file "01 Chris Gray - If They Could Tax Flamboyance.flac" in folder "Chris Gray and Malcolm Moore — (2010) Mysteries of the Ampalaya — [AMR-19R]" (cannotWrite(file:///Volumes/Music/Singles%20:%20EPs/Deep%20House/Chris%20Gray%20and%20Malcolm%20Moore%20%E2%80%94%20(2010)%20Mysteries%20of%20the%20Ampalaya%20%E2%80%94%20%5BAMR-19R%5D/01%20Chris%20Gray%20-%20If%20They%20Could%20Tax%20Flamboyance.flac))

Backlog_Mp3tag.txt (2.3 KB)

5

Thank you for the error log. It's the exact same problem as with the topic you've linked to in your initial post.

When requesting the file length via fstat(), the system returns EBADF (error 9 in the log), which means Bad file descriptor.

In plain language, this means that the handle to the previously opened file is no longer valid. What's confusing is, that the other tools you've mentioned can write to the file without any problems. It's possible that they're using a higher-level API for file operations that doesn't result in the issue with ReadyNAS.

I've created an internal version for testing and have sent the link via PM. Please try this version and let me know if it changes anything.

6

… and that appears to have worked!

I dragged and dropped a single file from my NAS using Finder and ran the action to add a UUID and no error appeared… just to be sure and confirm, I ran metaflac --show-all-tags:

metaflac --show-all-tags /Volumes/Music/Singles\ :\ EPs/Deep\ House/Chris\ Gray\ and\ Malcolm\ Moore\ —\ (2010)\ Mysteries\ of\ the\ Ampalaya\ —\ [AMR-19R]/01\ Chris\ Gray\ -\ If\ They\ Could\ Tax\ Flamboyance.flac
ALBUM=Mysteries of the Ampalaya
ALBUMARTIST=Chris Gray and Malcolm Moore
ARTIST=Chris Gray
DESCRIPTION=Cat#: AMR-19R | ``http://www.discogs.com/release/1969275
GENRE=Electronic, Deep House
TITLE=If They Could Tax Flamboyance...
MUSICBRAINZ_TRACKID=DEB3CE8B-1C20-41AE-94ED-AE755E4A89CB
DATE=2010
ORGANIZATION=Altered Moods Recordings
TRACKNUMBER=1

Edited to add, it also worked when dragging in a complete folder. Let me know of anything additional you want me to test and I’ll get to it this weekend. Thanks!

7

Excellent! I've created another internal version for testing and have sent the link via PM. Please try this version and let me know if it's still working.

9

Thanks, tried it (dragging a folder into it) and it didn’t work with 1.97-beta.2.2.

10

Thanks for trying the updated version. It looks like any attempt to use file locking on the ReadyNAS results in bad file descriptors.

I've created another internal version for testing and have sent the link via PM. It now tries to detect if the change is performed via a network connection and only uses file locking when performed locally.

11

Florian,

if you want me to test this, if possible with the purchased App?, on a synology nas with latest DSM send me a link as well. Happy to test.

Sequioa 15.6.1

12

Thank you, @mjcm ! I've changed things again and I'm now trying to detect the EBADF bad file descriptor situation and try to workaround the issue.

Let's see what's happening on the affected ReadyNAS. If it's working file, I'll send you a link and would be happy if you could try it on your system.

13

Thanks for the new beta 1.97-beta.3 but unfortunately it didn’t work: dragging folder, dragging file + opening folder from Mp3tag.

14

Thanks again! It looks like I can't transparently work around the issue, because the file descriptors become invalid at random points in time on the ReadyNAS.

I've created another internal version for testing and have sent the link via PM. It now has a configuration setting to disable file locking for files on network shares which you can set via Terminal.app and this command

defaults write app.mp3tag.Mp3tag NetworkFileLockingEnabled -bool no

15

1.9.7-beta.4 is a go! :ok_hand: :ok_button: :check_mark:

This was dragging a folder in from Finder.

16

Excellent! Thanks so much for your help in testing this.

I was hoping for a solution which works without setting any configuration options, but I think it's as good as it gets (for now).

I'll include the workaround with the next release, so that it gets available for everyone with writing problems on a NETGEAR ReadyNAS.

For future reference, the configuration setting to disable file locking for files on network shares can be set via Terminal.app and this command

defaults write app.mp3tag.Mp3tag NetworkFileLockingEnabled -bool no

After starting Mp3tag, it detects this setting and works around the ReadyNAS issue.