[PLUG] Android Filesystems

[John Jason Jordan]

I'm tearing my hair out.

I have a 1TB USB 3.0 drive with two plugs, Type A on one end and Type C
on the other. I bought it to simplify moving files to and from my
laptop and my phone, which is Type C.

I have been told that Android uses EXFAT and Linux can read/write EXFAT
as well, since kernel 5.4, which I have. I formatted the drive on the
laptop as EXFAT and copied some files to it. Then I removed the drive
from the computer and plugged it into the phone, which announced that
there was an 'unsupported USB drive' and it had to be formatted to be
used. I formatted it on the phone, ignoring the warnings that all data
would be erased. When the formatting was finished I removed the drive
from the phone and put it back into the laptop, expecting that I would
have to copy the files to it again, but when I looked at it all the
files were still there.

So then I put the drive back in the phone, but no files. All that I
find are a root folder 'Android,' with sub-folders:

	Android
		data
			com.android.vending
				files
			com.google.android.apps.translate
				files
					olvp3
						v5
							02, 25, + more,
							all empty
					com.microsoft.skydrive
						cache
					com.samsung.android.aremojiedito
					com.samsung.android.messaging
						cache
						files
					com.sec.android.gallery.3d
						files
					con.sec.imsservice
						files
					org.kman.AquaMail (I installedthis)
						cache
						files

All of the above folders are empty. My files appear when the drive is
inserted into my laptop (Xubuntu 20.04.1), but Android can't see them.

I thought that EXFAT might be great idea for USB drives, since
everything can read it. No permissions, but that may be a good idea for
USB drives. However, considering all the pain I have suffered trying to
get it to work, I'd rather use ext4. I mean, at least it effin' *works*.

I inserted an ext4 USB drive into the phone, and nada. The phone
doesn't even see it. I have poked all over the net and many places say
that Android is supposed to be able to read/write to ext4, but not in
my experience.

Maybe I need some utility on my phone to get it to read/write to ext4.
Does anyone have any clues?