[Gluster-users] Why does NUFA not allow mounts even from trusted peers without a subvolume?

[Michael Lampe]

I've installed GlusterFS on our 23-node Beowulf cluster. Each node has a 
disc which provides a brick for the GlusterFS volume and every node 
mounts this volume. The NUFA translator is ideal for the code we run and 
everythings works fine so far.

Only problem is the frontend node, which does not have a subvolume: 
After I've turned on NUFA, it no longer can mount the volume. :(

[2013-12-04 21:35:44.262738] E [nufa.c:641:init] 0-gv0-dht: Could not 
find specified or local subvol
[2013-12-04 21:35:44.262766] E [xlator.c:390:xlator_init] 0-gv0-dht: 
Initialization of volume 'gv0-dht' failed, review your volfile again
[2013-12-04 21:35:44.262783] E [graph.c:292:glusterfs_graph_init] 
0-gv0-dht: initializing translator failed
[2013-12-04 21:35:44.262799] E [graph.c:479:glusterfs_graph_activate] 
0-graph: init failed

Is there any technical reason for treating things this way? Why cannot 
NUFA fall back to distribute, like it does when the local subvolume has 
not enough free space?

Or is there a better way to include a frontend node?

-Michael