Simple script to setup a cinder volume in a file.

cinder-setup-volume.sh

#!/bin/sh

if [ "$1" == "" ]; then
  echo "[ERROR] Please specify volume size. Usage: $0 3G"
  exit 1
fi

# Create a file
dd if=/dev/zero of=cinder-volumes bs=1 count=0 seek=$1
# Create a loop device
losetup /dev/loop2 /cinder-volumes
   
# Make a auto mount
echo "losetup /dev/loop2 /cinder-volumes; exit 0;" > /etc/init.d/cinder-setup-backing-file
chmod 755 /etc/init.d/cinder-setup-backing-file
ln -s /etc/init.d/cinder-setup-backing-file /etc/rc2.d/S10cinder-setup-backing-file

# Create cinder volume
pvcreate /dev/loop2
vgcreate cinder-volumes /dev/loop2