The Nautilus Trash feature stopped working, so I could only delete a file completely, rather than move it to the trash. Here’s what’s happening, and how to restore it.
Trash folders, named .Trash-uid, are created by Nautilus when you press “delete” or move a file to the trash. .Trash folders are created in the root directory of a mounted volume.
I was having trouble using the Trash on a mounted volume. I think I deleted the Trash folder, and Nautilus wasn’t creating one. So, I could permanently delete a file, but I couldn’t delete it to the Trash.
The problem was that my mounted volume was owned by root, and the permissions didn’t allow other users to create files in the root. That was exactly what I wanted: I didn’t want to create too many directories in there. I owned the subdirectories.
The fix was to do this to this disk’s root, to enable writing:
sudo chmod o+w .
Then, I deleted a file by pressing “delete”. This caused Nautilus to create a new .Trash folder.
Then I typed this command to disable writing in the root again:
sudo chmod o-w .