1a - Remove mount point /test of /dev/sda1 (8.00 GiB) from /etc/fstab -> 1b
1b - Unmount /dev/sda1 (8.00 GiB) at /test -> 1c
1c - Delete ext4 on /dev/sda1 (8.00 GiB) -> 2 3a
2 - Shrink partition /dev/sda1 from 8.00 GiB to 4.00 GiB -> 3a
3a - Create ext4 on /dev/sda1 (4.00 GiB) -> 3b
3b - Mount /dev/sda1 (4.00 GiB) at /test -> 3c
3c - Add mount point /test of /dev/sda1 (4.00 GiB) to /etc/fstab ->
