Hi:
I hava a tp-link router with usb port, plugged in a portable hard drive, it can remote access through FTP.
Now, I wish joplin's data could be synced to this portable drive.
Thanks!
Depending on the device, you can mount the ftp share to the file system and then sync to it using "File system" as the target...
yes，it worked， thank you。 
what about android???
@bradwww Can be done with the RoundSync app ( Round Sync - Rclone for Android | F-Droid - Free and Open Source Android App Repository ). It would be recommended to serve the FTP connection via a WebDAV server using it, to get around performance issues with file system sync on Android, then connect Joplin to it using WebDAV. That will require that you have a background / foreground service from RoundSync running all the time though, to keep the WebDAV server active.
i thought joplin supported webdav out of the box? if so why would you need a sync program? i’m having serious issues running joplin on onedrive - can’t finish the sync without errors. is dropbox better?
Yes it does support WebDAV out of the box, but I’m suggesting if you want to have FTP support on mobile, your best option is to serve an FTP connection over WebDAV - that requires running an actual server (not publicly accessible) on your device 24/7.
If you’re just wanting a free provider and OneDrive isn’t working well for you, then yeah try Dropbox instead.
i was only asking about ftp because i have a server for it. if you are saying dropbox would likely be more reliable that onedrive (sync errors) then i would try that ASAP - is that what you are saying? would dropbox be better than webdav? can i simply copy the folder to dropbox and try to sync - or let joplin somehow move everything? i have thousands of sync errors. thanks!
Yes I’d say Dropbox is more reliable than OneDrive. Certainly Dropbox would be better than any free WebDAV providers, but if you self host or find a good WebDAV provider with servers based geographically close to your country, you would likely get faster sync with a WebDAV provider than Dropbox (but not as fast as Joplin Cloud / Server).
can i simply copy the folder to dropbox and try to sync
No, don’t do that. See How to fix synchronisation issues and start over
IMPORTANT: Make sure you have a working jex backup before you delete anything. To test the backup, create a new profile on the desktop app, import the jex and then make sure everything you want is there
speed is not an issue. why would i delete anything? that’s what a duplicate finder is for. i have my own ftp server and would like to add webdav to it but if dropbox works that’s fine. please advise if you can sort by note name AND last modified date so i can keep the newer ones? thanks.
Don’t attempt to manipulate the Joplin files on the server is what I’m saying.
If you don’t want to use the full reset process which I linked, you can just switch the sync target to Dropbox in the Joplin app on all your devices and the app will automatically upload the data there / syncronise the required local metadata on each device (but the first sync on every device could take a while). But if you do this, I repeat, don’t change anything on the server. Don’t copy the folder from OneDrive to Dropbox. Let the Joplin app upload the data to Dropbox on the first sync, otherwise you’re going to cause problems if you try to upload it yourself.