The 1 TB drive is owned by root, so I, normal user, can't add folders
or files. No other users will ever be added to this PC. What is the
recommended way to make the 1 TB drive (listed in Other Locations) a
device I can add folders and files to?
Assuming the filesystem on the 1TB drive's partition is a Unix/Linux filesystem that supports Unix/Linux type permissions ...
Mount it with like:
mkdir ~/my_mnt
then:
sudo mount /dev/sdyx ~/my_mnt
changing sdyx to the actual partition name on the 1TB drive e.g. sdb1.
That is if it’s not already mounted, or otherwise use its current mount-point instead of ~/my_mnt below.
Then change the ownership of the mount-point(while the partition/block device is mounted) to the user:group of your choice like so:
sudo chown user:group ~/my_mnt
or to your current logged-in user:primary_group like so:
sudo chown "$(id -un):$(id -gn)" ~/my_mnt
This will permanently change the ownership of the top-level(AKA root) directory of the mounted filesystem at ~/my_mnt i.e. the filesystem on the 1TB drive's mounted partition to the supplied user:group giving them full permissions to create directories/files under it.
Notice:
This is the normal situation for data storage disks/partitions like e.g. external USB disks, when you format them to a Unix/Linux filesystem, the invoking user i.e. your user becomes the owner of that filesystem’s top-level directory and it’s even the normal behavior for non-Unix/Linux filesystems when you mount them their top-level directory becomes owned by the invoking user as well AKA user-space virtual filesystem mounts.
