I have an RDO packstack Newton setup with 1 controller node and 2 compute nodes, all on VMs run by KVM.

The cinder volume service is on the controller node as well. It's LVM accessed with ISCSI.

The write speed on a volume attached to an instance is extremely low, ~5MB/s

#  dd if=/dev/zero of=baloon bs=1048576 count=200 oflag=dsync
200+0 records in
200+0 records out
209715200 bytes (210 MB) copied, 39.5572 s, 5.3 MB/s

The network speed between compute and storage(controller) nodes is 100MB/s

Any troubleshooting and tuning tips are appreciated.

Thanks.