unable to create preallocated image with gluster network protocol

Unable to create preallocated image with gluster protocol

Version: qemu-img-0.12.1.2-2.479.el6.x86_64
Platform: RHEL 6
I have tried creating preallocated image as follows :

qemu-img create -f qcow2 -o preallocation=full gluster://localhost/vol1/vm1.img 10G

I see error a follows :
[root@ ]# qemu-img create -f qcow2 -o preallocation=full gluster://localhost/rep3vol/vm1.img 5G
Formatting 'gluster://dhcp37-61.lab.eng.blr.redhat.com/rep3vol/newvm3.img', fmt=qcow2 size=3221225472 encryption=off cluster_size=65536 preallocation='full' 
Unknown option 'preallocation'