On my Chromebook, I followed these steps to make an ext4 partition on a USB drive. Once the process was completed, when the the USB drive is plugged back in, Chromebook detects the drive and mounts it. No problems there.
If I were to mount the USB drive on a Linux host,
touch a new file or something, eject and then plug back into the Chrome book, I get the popup saying the media is not recognized. If I were to mount manually from crosh/shell, I get the following error:
mount: /media/removable/foo: wrong fs type, bad option, bad superblock on /dev/sdb1, missing codepage or helper program, or other error.
This is puzzling because the drive is not corrupted at all as I can still mount/read/write same drive on the a Linux host.
Essentially, Chromebook refuses to mount an FS that was used--and is still usable--elsewhere. What could be going wrong here? How can I troubleshoot this?