I've reconfigured my setup (good succes below, but need clarity on gluster option): Two nodes total, both running virt and glusterfs storage (2 node replica, quorum). I've created an NFS storage domain, pointed at the first nodes IP address. I've launched a 2008 R2 SP1 install with a virtio-scsi disk, and the SCSI pass-through driver on the same node as the NFS domain is pointing at. Windows guest install has been running for roughly 1.5 hours, still "Expanding Windows files (55%) ..." top is showing: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3609 root 20 0 1380m 33m 2604 S 35.4 0.1 231:39.75 glusterfsd 21444 qemu 20 0 6362m 4.1g 6592 S 10.3 8.7 10:11.53 qemu-kvm This is a 2 socket, 6 core xeon machine with 48GB of RAM, and 6x 7200rpm enterprise sata disks in RAID5 so I don't think we're hitting hardware limitations. dd on xfs (no gluster) time dd if=/dev/zero of=test bs=1M count=2048 2048+0 records in 2048+0 records out 2147483648 bytes (2.1 GB) copied, 4.15787 s, 516 MB/s real 0m4.351s user 0m0.000s sys 0m1.661s time dd if=/dev/zero of=test bs=1k count=2000000 2000000+0 records in 2000000+0 records out 2048000000 bytes (2.0 GB) copied, 4.06949 s, 503 MB/s real 0m4.260s user 0m0.176s sys 0m3.991s I've enabled nfs.trusted-sync ( http://gluster.org/community/documentation/index.php/Gluster_3.2:_Setting_Vo... ) on the gluster volume, and the speed difference is immeasurable . Can anyone explain what this option does, and what the risks are with a 2 node gluster replica volume with quorum enabled? Thanks,