usando o comando df -h.
apareceu isso, o hd escravo ta na ultima linha.
fiu@fiu-MW-H61H2-M2:~$ df -h
Sist. Arq. Tam. Usado Disp. Uso% Montado em
udev 2,9G 0 2,9G 0% /dev
tmpfs 594M 1,8M 593M 1% /run
/dev/sda1 458G 8,4G 426G 2% /
tmpfs 2,9G 16M 2,9G 1% /dev/shm
tmpfs 5,0M 4,0K 5,0M 1% /run/lock
tmpfs 2,9G 0 2,9G 0% /sys/fs/cgroup
/dev/loop0 2,3M 2,3M 0 100% /snap/gnome-calculator/260
/dev/loop1 35M 35M 0 100% /snap/gtk-common-themes/818
/dev/loop2 3,8M 3,8M 0 100% /snap/gnome-system-monitor/57
/dev/loop3 15M 15M 0 100% /snap/gnome-logs/45
/dev/loop4 13M 13M 0 100% /snap/gnome-characters/139
/dev/loop5 91M 91M 0 100% /snap/core/6350
/dev/loop6 7,5M 7,5M 0 100% /snap/canonical-livepatch/58
/dev/loop8 141M 141M 0 100% /snap/gnome-3-26-1604/74
/dev/loop7 174M 174M 0 100% /snap/spotify/34
tmpfs 594M 12K 594M 1% /run/user/121
tmpfs 594M 36K 594M 1% /run/user/1000
/dev/sdb1 466G 11G 456G 3% /media/fiu/Matrix