if modprobe overlay; then
UNION_TYPE=overlay
UNION_OPTS="upperdir=/cow/up,lowerdir=/rofs,workdir=/cow/work"
mkdir -p /cow/up /cow/work
elif modprobe overlayfs; then
UNION_TYPE=overlayfs
UNION_OPTS="upperdir=/cow,lowerdir=/rofs"
elif modprobe aufs; then
UNION_TYPE=aufs
UNION_OPTS="dirs=/cow=rw:/rofs=ro"
else
. /scripts/functions
panic "Could not load neither overlayfs nor aufs."
fi