volume client1
  type protocol/client
  option transport-type tcp    
  option remote-host 127.0.0.1     
  option transport.socket.remote-port 7777
  option remote-subvolume brick1      
end-volume

volume writebehind
  type performance/write-behind
  option cache-size 4MB
  option flush-behind on  
  subvolumes client1
end-volume