If we use Ganesha will GPFS ,  user api
will be NFS and we will lose most of GPFS functionalities,
like writing into single file parallelly.

Is my understanding correct?

If so, how can we get parallel write performance on a file
with NFS Ganesha?

Is my better option is to give up on Ganesha and use
Luster/Gluster directly? I need open source code.

-alok