Sync to Android SD card

Idea is to sync large music library from macOS to Android running Lineage 19.1 and Syncthing-Fork 1.19.1.1 (Syncthing 1.20.1) with SD card to store hold the files. Should that work? Search for SD card does not bring up any results on Search — Syncthing documentation.

LineageOS 19 is Android 12, so it should work fine with the SD card, at least when using the official Syncthing app.

Unsure how to select SD Card as Directory folder to sync to. In Advanced storage path overview I see a few folders /storage/emulated/0, …/DCIM, …/Documents and so forth. But the sd card does not seem to show up - only internal storage seems to be available for selection.

Just to confirm, you’re using official Syncthing application, right?

Was running Syncthing-Fork. Before initial setup read that Syncthing-android is essentially in maintenance mode - it still works, but not many changes happening. The fork is faster paced with added features (Syncthing & Syncthing Fork - #2 by imsodin) so opted to go with Syncthing-Fork.

Maybe that was a bad decision so lets switch to Syncthing-Android. Used backup > export option in Syncthing-Fork and backup > import option on Syncthing. This did not work it seems. I force closed all apps after a while to find that when opening Syncthing it shows a Loading spinner. After some time it showed Syncthing is taking very long to load. Use the logs to check for any errors.

Should I just remove both apps and start with a fresh install of Syncthing to get things working again hopefully?

Syncthing seems to be stuck on starting. It started once but maybe the backup import was a bad idea nad things got corrupted.

Did as described: removed Syncthing-Fork, re-installed and setup Syncthing.

For the main question how to sync to sd card: still unsure where to find the sd card in the Directory selection.

If you click on “Directory” when trying to create a new folder in the app, you should be presented with a screen similar to the following.

The folder picker comes from Android itself, so the exact look will differ depending on the OS version, manufacturer, and/or ROM. You should be able to navigate to the external SD card from there.

If you can’t see anything like that, can you share a screenshot of your screen then?

I see a similar view. Where would the sd card be expected to show?

Is there no option to switch to the external sd card under the menu in top-left corner?

The top right dots show the single option Don't show hidden files.

I’ve just checked it myself with an actual SD card. The switch is in the left slide-out ☰ menu.

Thanks for your patience and trying to help me out. However I do not see a slide-out menu on the left.

I also don’t see it in your previous screenshot of the view to select directory.

The menu seems to be only available when there’s an SD card detected in the phone. I had no SD card inserted when the previous screenshot was taken.

Can you access the card normally when using the built-in file manager?

Now we’re getting closer. I added the sd card and LineageOS automatically offered to format the sd card. I accepted and opted to go with using the sd card only in the phone, which is known to cause less trouble than the adaptive storage option.

Settings > Storage Manager shows the SD Card. Surprisingly when selected, it shows a few GB of used data despite me not actively telling LOS to put apps or system data onto the sd card. And yet it claims over 3 GB used for Apps with the only app shown being Syncthing with 77.66 MB which doesn’t really add up.

Happy to format the sd card and give it another try, but I don’t know how to trigger that option. It automatically showed after inserting the sd card. Storage Manager only allows to Format as portable. But I don’t want a portable sd card, potentially causing even more confusion than I already have tying to use the sd card.

Not an expert, but from my understanding, the option you’ve selected (i.e. “to use the card only in the phone”) is specifically the adapted storage. By doing so, you essentially replace your internal storage with the SD card. This means that you end up with no external SD at all.

On the other hand, the card needs to be formatted as portable in order to be displayed as a separate storage. Please be aware that you will lose everything stored in the so called internal storage (i.e. the /sdcard partition) if you format it like that now, so make sure you back all the files up before doing so.

Portable is the desired option and this is finally resolved:

  • moved apps to internal storage
  • reformatted sd card to portable
  • setup sync with Syncthing

Happy user :tada:

Would be great if LOS explained formatting options in greater detail for users not familiar. At least today I moved from sd card idiot to knowing, which option not to choose in the future.

It’s all easier if you go the really unknowing route: Buy a (usually pre-formatted) SD card, put it in the phone, THEN start looking at the apps which should use it. Glad you figured it out now.