I've been trying out Joplin (2.9.17) and liked it. It was installed on one iMac (Catalina). All was well until I synced with Dropbox. Sy8nc appeared to work normally. I left it in the background for a time, then quit it. Three hour later I came back to discover my Dropbox (2GB) was full. There were over five thousand invisible files. My other syncing process had replicated these in two other places. It took me an hour to sort it out, deleting Joplin and all support files.
What could have caused this? I've been evaluating Evernote, Apple Notes, and Joplin and was inclined towards Joplin, but now I'm reluctant to try again as I can't have this sort of thing happening.
This will all depend on how many notes you've got and how large they are. You may want to check Help > Synchronisation Status in Joplin to see what your overall note file number looks like. As for the size, you can check your Joplin profile folder and see how much space the database and the resources folder take up. Also, please check your note history settings as old note versions (including deleted ones) can take up quite a bit of space. To be honest, 2GB isn't that much, unless you deal with pure text notes only (i.e. no large images, PDFs, videos, etc.).
I have only 114 notes, and only two or three with images. The total amount is only about 4Mb. There was about 900 Mb free in my Dropbox and it was entirely filled up with invisible files - all small, but 5,000 odd of them. Some were some sort of error message, some just had long names of random letters and numbers. The inititial sync seemed to work as expected. All this clutter was only apparent (the files being invisible) when Dropbox announced it was full.
With only 4 MB worth of notes, something does sound suspicious here. For troubleshooting purposes, it would probably be the most beneficial if you could provide samples of those erroneous files, if you still have access them, that is.
I had deleted them all. However, I used Time Machine to look at the Dropbox folder. I found a lot of folders with names like '.tmp.driveupload (Selective Sync Conflict 42)'. That one contained two files which are synced in Dropbox but are nothing to do with Joplin (though the filenames were numbers, not the originals). They started appearing at the time I enabled sync in Joplin. None of which of course make sense.
I also looked at the activity log for the backups of my Mac to Google Drive, and found uploads of files with similar numbers to those mentioned above, and also files with names like '3d6838bce0a5d4036dac01410068' (that isn't complete, it's truncated in the list and the actual file is deleted).
It may not have directly been Joplin's fault as such, but evidently its sync triggered something.
Please consider this thread closed. My thanks to tomsz86 for his anwers. However taking a number of factors into account, including that I can't risk trying to sync it in Dropbox again and OneDrive is apparently not hightly regarded, I've decided to go with Apple Notes. I really like Joplin, though with one or two reservations, but for various reasons I think Notes fills the bill slightly better for me .
I’ve had Dropbox sync loose pictures, partial notes, conflicts galore. Between using 3 devices to synce between, I found when I dropped down to 2 devices it was a bit better, but still loosing files is just that.
Dropbox could be doing something, be it intentional or not, when multiple synced are taking place it’s tossing stuff or it just can’t handle it. I gave up using DB. It’s been more successful wit Onenote, though I’d prefer leading to do a Ubuntu server with Portainer and my own Joplin server…in time, in time.
I know I said I'd decided to go with Apple Notes, but having had it lose a couple more notes (I did have backups) I'm back with Joplin. I'm syncing it between two Macs by doing precisely what we are advised not to do: I placed the 'joplin-desktop' folder in Dropbox and routed the app on each Mac to it using a symbolic link. It works perfectly well (so far) with a lot of use and rebooting as I've worked on the css. The syncing is immediate so no danger of quitting it before the next sync. The big caveat is that it's vital not to have the app running on both Macs at the same time. That would cause chaos. I don't necessarily recommend this method: it's OK for one person using a couple or three desktop computers but not for more widespread use. I export in HTML automatically once a day (using Keyboard Maestro) to my Documents folder, which is backed up to Google Drive. My android tablet can access the backup folder through Google Drive and can read, but not write to, the text of notes (images don't show). With some tweaks to the appearance I'm very pleased with the result: inevitably there are one or two compromises but on the whole it's working well.