How to create a virtual writable volume?

Question

linux

Good day to all.
We have a Linux Debian host. It is necessary to create a virtual partition in this environment (most likely some kind of img, iso and etc. image), with the ext2 / ext4 file system. The created image should be subsequently writable and mounted as a regular ext4 volume via /etc/fstab
Tell me, is this even possible and in which direction to dig?

Answer 1

1. Create a file of the desired size
2. Mount it as a loop device
3. Format
4. Mount
mount /dev/loop0 /mnt/image

Answer 2

Slightly improved 1st answer:
create file:
fallocate -l 1G /file
mkfs.ext4 -Fm0 /file
mount
either mount -o loop,noatime,nodiratime /file /mnt
or via fstab with options rw,loop,noatime,nodiratime