It's possible to use the Fire TV as a NAS with music files stored on the external USB drive. Install DroidNAS on the Fire TV - set up fstab on the LMS server to mount the DroidNAS files.
The only problem is that DroidNAS doesn't have an option to autostart - so, in the event of a Fire TV reboot, you have to restart the DroidNAS and remount the drive. Otherwise, it works very well.
There's another app called SMB Server which has an autostart option when it detects the wifi connection, but I haven't been able to test it on the Fire TV.
The only problem is that DroidNAS doesn't have an option to autostart - so, in the event of a Fire TV reboot, you have to restart the DroidNAS and remount the drive. Otherwise, it works very well.
There's another app called SMB Server which has an autostart option when it detects the wifi connection, but I haven't been able to test it on the Fire TV.