4096 0.file
4096 1.file
4096 2.file
4096 3.file
4096 4.file
20480 big.file

dd if=/dev/zero of=0.file bs=1024k count=4
losetup /dev/loop0 0.file
pvcreate /dev/loop0
# … repeat for all parts …
vgcreate -s 1m foo /dev/loop0 /dev/loop1 …
lvcreate -l 19 -n big foo
mkfs.btrfs /dev/mapper/foo-big

# Create MosaicFS disk image
# (the individual tile files will be stored in the directory 'disk.img')
mosaicfs create --number 76800 --size 4M disk.img

# Mount disk image
# (the virtual image is mounted as 'myimage' with a size of 300 GB)
mosaicfs mount disk.img myimage

# Create file system
mkfs.ext4 myimage

# Mount it
mkdir -p /media/mydrive
mount -o loop myimage /media/mydrive

# Unmount everything
umount /media/mydrive
fusermount -u myimage