GlsuterFSのNFS機能を使ってないのに /var/log/glusterfs/etc-glusterfs-glusterd.vol.log に↓こんなログが大量に出ていたら。

/var/log/glusterfs/etc-glusterfs-glusterd.vol.log

[2015-12-27 09:26:31.241557] W [socket.c:588:__socket_rwv] 0-nfs: readv on /var/run/gluster/3b8b9a076198b28c9e93ab3085a45842.socket failed (無効な引数です)
[2015-12-27 09:26:34.241924] W [socket.c:588:__socket_rwv] 0-nfs: readv on /var/run/gluster/3b8b9a076198b28c9e93ab3085a45842.socket failed (無効な引数です)
[2015-12-27 09:26:37.242350] W [socket.c:588:__socket_rwv] 0-nfs: readv on /var/run/gluster/3b8b9a076198b28c9e93ab3085a45842.socket failed (無効な引数です)
[2015-12-27 09:26:40.242810] W [socket.c:588:__socket_rwv] 0-nfs: readv on /var/run/gluster/3b8b9a076198b28c9e93ab3085a45842.socket failed (無効な引数です)
[2015-12-27 09:26:43.243294] W [socket.c:588:__socket_rwv] 0-nfs: readv on /var/run/gluster/3b8b9a076198b28c9e93ab3085a45842.socket failed (無効な引数です)
[2015-12-27 09:26:46.243760] W [socket.c:588:__socket_rwv] 0-nfs: readv on /var/run/gluster/3b8b9a076198b28c9e93ab3085a45842.socket failed (無効な引数です)

ボリュームの nfs.disabled を確認して false だったら true に変えてあげましょう。

[root@r17 glusterfs]# gluster volume get vol1 nfs.disable
Option                                  Value
------                                  -----
nfs.disable                             false
[root@r17 glusterfs]# gluster volume set saba2 nfs.disable true
volume set: success