OVM 3.0.1 | VM guest IO is slow

Hi Guys,

Here is my setup, 

1x OVM Server, hostname ovmsvr01 with 16 cores and 16GB RAM

1x OVM Manager , ovmm as guest of OVM server, with 4 cores and 4GB RAM

2x Oracle Linux 5 , poc1 and poc2 with 4 cores and 4GB RAM 

1x NFS repository from Netapp filer , keep all the virtual disk

test makefile in poc1 (with sit on NFS repository)

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[root@poc1 u01]# time dd if=/dev/zero of=test bs=1024 count=1000000

1000000+0 records in

1000000+0 records out

1024000000 bytes (1.0 GB) copied, 107.39 seconds, 9.5 MB/s

real    1m47.464s

user    0m0.686s

sys     0m20.715s

[root@pe3poc1 u01]# time dd if=/dev/zero of=test bs=1024 count=100000