Replying to a slightly ancient post, here, but as I've just got round to getting myself a MicroSD...
This is probably a wider issue than just VLC.
Android's whole use of filesystem is taking a while to get my head round. As far as I can tell, most of the filesystem is off-limits; there's a 'shared' directory in the internal memory, which each app gets a subdirectory in, and can usually see only that private directory, but you can give it permission to see the rest of the shared directory. The SD card is even less visible; a few apps (mostly video players, music players, and file managers) can see it, but most other apps can't see it at all. However, most apps can read a file if it was sent from another app (e.g. a file manager), though they may not be able to write to it, and won't know where it is in the filesystem. And if you have root, you can do more stuff, but only if you know where it is...
Or something vaguely like that! (Please correct me on any of that...)
Many apps don't use files at all -- or at least, pretend not to. Some include some form of file selector, while others can only use files opened from a link or file manager. Each seems to have a different combination of directories it can see. A few can open multiple files at one (e.g. Jota+ in tabs).
The whole thing seems a confusing nightmare! Apps having to roll their own file selectors, and their own ways of opening multiple files (or managing multiple instances)... Isn't the OS supposed to handle all that sort of stuff???
Yes -- I'm finding myself fairly frustrated! I decided (still being new to Android) that it would be most convenient to install it as "Portable Storage" The first shock was that it reported the card was "corrupted"! Eventually I found out -- as others have before me -- that the card was formatted ExFAT, and the Gemini doesn't know about that! With my heart slightly in my mouth, I told it to go ahead and reformat it as FAT32, and fortunately it worked. I can still access the card on my (Linux & Haiku) laptop.
However, actually using the card on the Gemini is generally a mess! I can use FileManager to transfer to and from it, and I managed to link it in to Termux's 'storage' directory. But most apps have no idea that it's there. The Jota editor, for instance, refuses to write to it. I can ask the FileManager to open a file from there in Jota, and that works, but when I try to write it back, Jota refuses to do so.
As one of the main reasons for thinking I wanted the external card was to minimize the "wear" on the internal drive, this is all rather annoying! As there are many other ways of transferring files to other machines, and popping the card out would be a pain anyway, I should probably change my mind and reformat it as Internal Storage. But again I have little idea what the results will be.
How, for instance, is the card as Internal Storage seen? Is it 'parallel' to the normal storage, or somehow merged so you don't know which drive is being used? Ae all the sub-folders duplicated, or what?
Enlightenment appreciated.
