Will create 64 GB disk and mount it:
dd if=/dev/zero of=cam03.img bs=1M count=64000
Create filesystem:
mkfs ext4 -F cam03.img
Create a mount directory
mkdir /mnt/cam03 chown nobody:nogroup /mnt/cam03
Mount image:
mount -o loop,rw,sync /mnt/MAIN/CCTV/cam03.img /mnt/cam03