I have syncthing for Windows setup on a laptop PC, and syncthing-fork setup on a Google Pixel 8. I used to have an older android device with a similar setup; I recreated the folders as I began to transition to the new Pixel 8 device, using syncthing to transfer my files over.
One of these folders is a large image/video gallery containing 42,659 files, totaling at 57.9 GB’s. According to the GUI page on the Windows PC, there are 3903 files(3.92 GB’s) that have yet to sync. These files are reported to all be last modified by the PC. Their modified dates are all over the place from the last 5 years or so. I have tried removing and re-creating the folders twice now, but syncthing continues to get stuck on these specific 3903 files. I have also tried copying the files over manually, but 1. I cant find pattern that groups these files together so I can copy them alone, and 2. USB file transfer from Windows to Android through Windows explorer leaves a lot to be desired. I have already ran into issues trying to copy the gallery in its entirety, and I’m too concerned with the possibility of data loss to try it again.
I have other sync folders setup between these two devices that are working normally. I can even add new images/videos to the gallery that is having issues, and they will be added/synced correctly.
I do not know what log files would be useful to post. I enabled fs and scanner debugging, but do not immediately see anything relevant to the gallery folder. Also, the gallery is of an adult nature and I do not want to be posting file names publicly in a log file. It it quite frankly embarrassing. I apologize in advance for not having more information; I didn’t see a FAQ page about what information is generally helpful for support threads. I am also not sure if this was a correct place to post, considering I am using syncthing-fork.
My guess is that there are “illegal” characters in the filename of these files. Turn your attention to one of them and identify characters which might be troublesome. Remove one such character at a time and see if it gets transferred. Good luck!
There should be an error for each file in the web GUI under “failed items”, after it’s tried to sync them. (Though maybe not visible while a sync attempt is ongoing.) The error message may be a hint. My first guess would be what @martinleben suggests, except, if the files are coming from Windows they should probably already be under the same naming restrictions…
My guess is that there are “illegal” characters in the filename of these files. Turn your attention to one of them and identify characters which might be troublesome. Remove one such character at a time and see if it gets transferred. Good luck!
I downloaded Bulk Rename Utility and checked the option to remove all ASCII characters past 127. It did not find any results in my image gallery that contained such characters. Majority of the images come from booru sites that use standardized, hashed file names, so its unlikely that any of these would contain illegal characters. There was a more recent download from a non-standard naming site, but if it had illegal characters in the names, BRU did not find them. I see some of those recent files are included in the out-of-sync files, but I don’t see any illegal characters in them.
There should be an error for each file in the web GUI under “failed items”, after it’s tried to sync them. (Though maybe not visible while a sync attempt is ongoing.)
Pretty sure that is what is happening. The sync is in progress, but nothing is ever reported for the 3903 files. Aside from them showing up as out of sync. Forgot to mention in the OP, but it took several weeks for the majority of the files to transfer. I expected it to take awhile, having read about the file system limitations on Android. So it took me a bit to notice the lack of progress on these remaining files. I’ve been sitting with these remaining, out-of-sync files for months now.
EDIT: I have never seen a “Failed Items” dialog, would that only show up if there were failed items to begin with? Otherwise, where would I find that in the web GUI?
Probably unrelated, but there are some strange sync conflict reports that only appear on the syncthing-fork UI. Using the web GUI on android doesn’t show them, and they also are not reported on the Windows side either. The syncthing-fork UI doesn’t seem to give me anyway to see more details of the supposed conflicts. I may post a screenshot later; it only shows one file with a conflict before the message gets cut off.
I am considering adding this gallery folder to another Windows 10 device. If its able to sync over all the files without issue, I will probably make a issue post on the github for syncthing-fork. I don’t know how long it will take to test, but I will edit this post and add the results after its done.
Well apparently I cant edit posts on this forum, so I’m sorry for double posting.
Adding the folder to another Windows 10 device worked fine, all files transferred successfully.
I also tried accessing the gallery folder over USB on the android device, and am now finding that I am entirely unable to do any file management over USB. I can look through folders, but trying to access the gallery folder causes the device to stop responding. I also cannot add new folders or open any files anywhere on the device. This is irrelevant to syncthing but I figured I would bring it up. I am at this point wondering if there is a hardware issue with my Pixel 8a. It should not be this difficult to troubleshoot file system access…
EDIT: Can edit this post though. I assume it gets locked out after awhile.
Eventually I was able to make a new folder inside an existing folder. Copied a few files that were reported as not syncing, and then used a file manager to transfer them to the gallery folder. But it turns out those files already existed in the gallery folder. I tried using the file explorer to search by file name to see if any other files already existed, but I am having similar load time issues as trying to browse over USB. I am quickly losing my patience with this device.
Sorry for the misunderstanding, I did do this. I was saying the Web GUI on the android device did not show these sync conflicts, only the native UI from syncthing-fork app did.
Looking through the folders now, I realize that the native UI was alerting me about sync conflict files that I simply forgot to delete/clean up. Deleting them from an unrelated folder seemed to work fine. Within the gallery, there were sync conflicts that were basically duplicates of the “.nomedia” files I was using to keep the images from showing up in unwanted places. I deleted them from the Windows side, and they added on to the list of files that refuse to sync. I also deleted them from the Android side, and now they also report not syncing to Windows, listing them as last modified by the Pixel8.
And while I am at it, there is a “.stfolder.removed-20250518-155432” within the gallery folder, that contains a “DO_NOT_DELETE.txt” file. Judging by the date, this was probably created when I deleted and recreated the folder in syncthing in a attempt to get it to see the remaining files. I do not know what I am supposed to do with it, or what purpose it serves. Reading other threads suggests that it is yet another duplicate and is safe to delete.