How to mount extra hdd permanently

> sudo -I blkid
/dev/sdb1: UUID="0687f976-6efe-4ac5-88dd-8fd863f8b8bf" TYPE="ext4" PARTUUID="1569f982-01"/dev/sda1: LABEL="cloudimg-rootfs" UUID="8ae3d910-2d2a-492d-8667-d0fa24e4d357" TYPE="ext4" PARTUUID="05ae307a-01"/dev/sdc1: UUID="e8abbf34-2cb2-471f-bac6-2a5caec81ad8" TYPE="ext4" PARTUUID="4c4db30a-01"

check uuid that you want to mount
>sudo nano /etc/fstab
Add this string end of file, but uuid must be your value, and ext4 also should be same with blkid information

UUID=e8abbf34-2cb2-471f-bac6-2a5caec81ad8 /media/datadisk ext4 defults,nofail    0       2

Thank you.