This post takes you through creating a partition, formatting it and finally mount it in the filesystem.
These procedures where tested on Linux Mint 19
$ sudo fdisk -l
The result will vary depending on the number of disk you have. On my computer I got these three entries:
/dev/sdaprimary physical disk/dev/sdbsecondary physical disk/dev/sdca USB memory stick currently plugged in- etc
$ sudo fdisk /dev/sdb
Substitute the physical disk for /dev/sdb.
Inside fdisk you type m to list the available commands. Use them to list free space SHIFT+f, list partitions p or create n or delete d one.
NOTE: You can specify size, rather than the ending sector numbers when partitioning. (Ie. type +200G to make a 200 Gigabyte partition.)
When you're finished, type w (for write) to perform the changes, or q to quit fdisk without performing the changes.
$ sudo mkfs -t ext4 /dev/sdb1
Substitute the physical disk and partition number for /dev/sdb1 (where sdb is the physical disk, and 1 is the partition number.)
$ mkdir /my-new-partition
$ sudo mount /dev/sdb1 /my-new-partition
Substitute the path in the file system where you would like to mount the partition for /my-new-partition. If you forget the leading / you wil mount it at a path relative to you current working directory.
If you want, you can mount the same partitions at multiple paths in the file system.
NOTE: The partition stays mounted only until next reboot. To make the changes persist over reboots, you need to write an entry in the /etc/fstab file. (See below)
You can list all mounted partitions with the df utility, like this:
$ df -h
You unmount a partition with umount:
$ sudo umount /my-new-partition
$ rmdir /my-new-partition
To make the mount persistent, you must edit the /etc/fstab table. Open it with you favorite text editor to add an entry (a new row)
/dev/sdb1 /my-new-partition ext4 defaults 0 0
Use space(s) or tab(s) to seperate the columns. (The exact number of spaces or tabs is irrelevant)
NOTE: Since partition names are somewhat dynamic (especially when moving disks to new ports, or USB-connected drives may not always be enumerated in the same order), you could lock down a specific partition in the /etc/fstab file by substituting the partition's UUID for /dev/sdb1. You can use the blkid utility to find a partitions UUID:
$ blkid | grep /dev/sdb1
Copy only the UUID="00000000-0000-0000-0000-000000000000" part from the string and use it like this:
UUID="00000000-0000-0000-0000-000000000000" /my-new-partition ext4 defaults 0 0