CORRECT TEXT
Create a 512M partition, make it as ext4 file system, mounted automatically under /mnt/data and which take
effect automatically at boot-start.

A.
# vim /etc/fstab

B.
# fdisk /dev/vda
n

C.
# fdisk /dev/vda

D.
# partprobe /dev/vda

Explanation:
# fdisk /dev/vda
n
+512M
w
# partprobe /dev/vda

# mkfs -t ext4 /dev/vda5
# mkdir -p /data
# vim /etc/fstab
/dev/vda5 /data ext4 defaults 0 0
# mount -a