I’m currently running plex on Ubuntu Gnome 17.04 and trying to use an external HDD as media storage. However, plex can not see any of the folders in the actual drive when creating a library, only the drive. When I specify manually which directory to point to the library scans come up empty. I’ve already tried the top solutions in the following threads:
The hard drive I’m using is NTFS and produced by Seagate.
Any help is greatly appreciated.
read the sticky threads at the top of this forum.
What sticky threads? Like post a link…
I’m really struggling with this.
I just got an expensive external with a case and Ubuntu 17 
Note: “USER” is the name of the folder of your user of linux.
I had the same problem… but I realize that it was problem of permissions in the folder “/media/USER” since if you look you have permissions “drwxr-x—+ root root” but there a sign of plus, this means that it have permissions ACLs and if you run the comment “getfacl USER” you can see:
file: USER
owner: root
group: root
user::rwx
user:USER:r-x
group::—
mask::r-x
other::—
with only add the user plex more the permissions with “setfacl -m ‘u:plex:r-x’ USER” you can give access to HDD external.
Luck!
