I have this curious question:
My situation it’s Two different Pendrive… in both of them there’s present the same files whit same names in a same question…
Pendrive A:
\Folder1\A.avi
\Folder1\B.avi etc etc
On PenDrive B the same file.
If i watch to end A.avi from pendrive A… i remove it and i insert on same USB the pendrive B whit same file structure.
A.avi it’s not mark as already wathced… it’s normal ?
Watched status is based on the full path to the file. Unless you changed defaults, OSMC mounts USB drives using a unique ID (either the label or the ID if there is no label), so the paths to the two drives would be different:
/media/DriveA/Folder1/A.avi
/media/DriveB/Folder1/A.aviOh it’s very interesting… because at this point, theoretically, if I give the same name at the both pendrive the watched database is perhaps “shared” between the two devices but i need to respect the same file structure ?
mmmmmm… need to test if it’s exact.
EDIT
You may be wondering why this question ? 
Let’s say I’m transferring the contents of a pendrive to a higher capacity one and instead of checking folder by folder to see what i already watch and what no i can simply use this little trick… if it’s works.
It would be much simpler to use trakt.tv and the trakt add-on to sync watched status across as many devices as you like. It also prevents loss of watched status of you ever lose a db to corruption.
Oh i never really understand how it’s works this addons… I have to give us a view sooner or later
Otherwise just 5 minutes ago i have made this little test:
I have copyed on my actually pendrive two totally different (different lenght… different size and also different bitrate) Mp3 files to root from pc using a ftp client.
I renamed it:
\A.mp3
\B.mp3
(and both file’s it’s mounted in \Media\64GB_1)
After that i have listen completely A.mp3. After that, ever by ftp from my pc, i have swithced the name of both file… A.mp3 renamed to B.mp3.
Also after that from osmc i have reopen the pendrive files and the result it’s… the B.mp3 (previously watched as named A.mp3) it’s not checked as “Already watched”. Also the A.mp3 (previously named B.mp3) it’s not marked as “already watched” so I don’t think kodi only manage this “database” on the name of the file itself…
Anyway I don’t think anyone has ever done this test before
It does, but “watched” status is not kept for files that don’t have video in them.
Ops… lol. I’m in quarantine and i’m so much free time
Next time i try to test it’s whit a .mp4 files or somethigs similar