Network traffic -> high system CPU usage

[fraenki]

Hi,

I'm running FreeNAS 9.1.1 in a VM (Linux-KVM, 4 CPU cores, 8 GB RAM, e1000 NIC) and currently testing UFS performance. I get acceptable write speed for my local dd-Test (50 MB/s), but network traffic is an issue.

I've tried several protocols: FTP, NFS, CIFS. All show the same result:
- top(3) shows a dramatic increase in system CPU usage (>70%)
- througput is only between 10-17 MB/s (slowest with FTP)

Other (plain) FreeBSD 9.1 VMs on the same hypervisor don't have this problem.

Any hint?


Thanks
- Frank