I've a simple 2-way replica volume, however it's capacity utilization is really inconsistent. I realize du and df aren't the same thing, but I'm confused how the brick and the NFS mount are not showing the same amount of capacity available. Underlying filesystem is XFS, and gluster volume is mounted using gluster NFS daemon - Note that volume is mounted on systems which run the bricks too. [root at rhesproddns01 ~]# gluster volume info openfire Volume Name: openfire Type: Replicate Status: Started Number of Bricks: 2 Transport-type: tcp Bricks: Brick1: rhesproddns01:/gluster/openfire Brick2: rhesproddns02:/gluster/openfire Options Reconfigured: nfs.rpc-auth-allow: 127.0.0.1 performance.write-behind-window-size: 128Mb performance.cache-size: 256Mb auth.allow: 10.250.53.*,10.252.248.*,169.254.*,127.0.0.1 network.ping-timeout: 5 performance.stat-prefetch: on nfs.register-with-portmap: on nfs.disable: off performance.client-io-threads: 1 performance.io-cache: on performance.io-thread-count: 64 performance.quick-read: on [root at rhesproddns01 ~]# df -h /opt/openfire Filesystem Size Used Avail Use% Mounted on localhost:/openfire 960M 881M 80M 92% /opt/openfire [root at rhesproddns01 ~]# du -sh /opt/openfire 174M /opt/openfire [root at rhesproddns01 ~]# df -h /gluster/openfire Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup00-gluster_openfire 960M 756M 205M 79% /gluster/openfire [root at rhesproddns01 ~]# du -sh /gluster/openfire 256M /gluster/openfire