Hi forum, ☺

I have a one terabyte external hard disk that is going to be mounted on my Debian system and used for storing multimedia, and a backup of my home folder. (As individual files.)

Please help me fill in the two red questionmarks below.

# mkfs.ext3 -m ? -O dir_index,has_journal,sparse_super -T ? -L "Terabyte storage" /dev/sdb1

First question mark: Do I need to reserve any or how many percentage of an one terabyte drive for the root user?
Second question mark: What file system type would my usage be grouped under? The various options did not make any sense to me.

Anything else I should specify for my usage?

By default, mkfs.ext3 reserves 5% for the super-user. That would make sense on a smaller partition that contains system files but it is far too much for a data partition, particularly when it is a large one. I would use -m 1 to reserve only 1%.

File system type is determined by the type of files you will be storing. The smaller ones are only recommended for a mail or news server. If you will be storing varying types of files, the best option would be to leave the T option out altogether.