Sorry for my late post, I'm having quite a tight schedule on other tasks. Yes jgreco I keep in mind your comment since you first mentioned it (just that I have no access to office during weekend). More iperf test result is as follows:
(1) Test with iperf
From CentOS-VM to FreeNAS:
CentOS-VM client:
[root@localhost ORCHID]# iperf -c 10.77.24.16 -i 10 -t 60
------------------------------------------------------------
Client connecting to 10.77.24.16, TCP port 5001
TCP window size: 23.2 KByte (default)
------------------------------------------------------------
[ 3] local 10.77.24.17 port 54561 connected with 10.77.24.16 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 1.10 GBytes 942 Mbits/sec
[ 3] 10.0-20.0 sec 1.05 GBytes 899 Mbits/sec
[ 3] 20.0-30.0 sec 1011 MBytes 848 Mbits/sec
[ 3] 30.0-40.0 sec 1.05 GBytes 905 Mbits/sec
[ 3] 40.0-50.0 sec 1.04 GBytes 895 Mbits/sec
[ 3] 50.0-60.0 sec 1018 MBytes 854 Mbits/sec
[ 3] 0.0-60.0 sec 6.22 GBytes 890 Mbits/sec
FreeNAS server:
[root@freenas ~]# iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
[ 7] local 10.77.24.16 port 5001 connected with 10.77.24.17 port 54561
[ ID] Interval Transfer Bandwidth
[ 7] 0.0-60.0 sec 6.22 GBytes 890 Mbits/sec
From FreeNAS to CentOS-VM:
FreeNAS client:
[root@freenas ~]# iperf -c 10.77.24.17 -i 10 -t 60
------------------------------------------------------------
Client connecting to 10.77.24.17, TCP port 5001
TCP window size: 32.5 KByte (default)
------------------------------------------------------------
[ 6] local 10.77.24.16 port 19453 connected with 10.77.24.17 port 5001
[ ID] Interval Transfer Bandwidth
[ 6] 0.0-10.0 sec 1015 MBytes 852 Mbits/sec
[ 6] 10.0-20.0 sec 1004 MBytes 842 Mbits/sec
[ 6] 20.0-30.0 sec 1007 MBytes 844 Mbits/sec
[ 6] 30.0-40.0 sec 994 MBytes 833 Mbits/sec
[ 6] 40.0-50.0 sec 1.00 GBytes 861 Mbits/sec
[ 6] 50.0-60.0 sec 1.06 GBytes 906 Mbits/sec
[ 6] 0.0-60.0 sec 5.98 GBytes 856 Mbits/sec
CentOS-VM server:
[root@localhost ORCHID]# iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[ 4] local 10.77.24.17 port 5001 connected with 10.77.24.16 port 19453
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-60.0 sec 5.98 GBytes 856 Mbits/sec
(2) Another test with iperf
Another test from CentOS-VM to FreeNAS server, piping dd_zero bigfile:
From CentOS-VM client:
[root@localhost ~]# iperf -c 10.77.24.16 -f m -M -m -n 1000000000 -F bigfile
------------------------------------------------------------
Client connecting to 10.77.24.16, TCP port 5001
TCP window size: 0.02 MByte (default)
------------------------------------------------------------
[ 4] local 10.77.24.17 port 54562 connected with 10.77.24.16 port 5001
[ ID] Interval Transfer Bandwidth
[ 4] 0.0- 8.6 sec 954 MBytes 934 Mbits/sec
From FreeNAS server:
[root@freenas ~]# iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
[ 7] local 10.77.24.16 port 5001 connected with 10.77.24.17 port 54562
[ ID] Interval Transfer Bandwidth
[ 7] 0.0- 8.6 sec 954 MBytes 931 Mbits/sec
(3) netcat
From CentOS-VM client:
[root@localhost ~]# dd if=/dev/zero bs=128k count=10k | nc -v 10.77.24.16 2222
Connection to 10.77.24.16 2222 port [tcp/EtherNet/IP-1] succeeded!
10240+0 records in
10240+0 records out
1342177280 bytes (1.3 GB) copied, 13.6917 s, 98.0 MB/s
From FreeNAS server:
[root@freenas ~]# nc -v -l 2222 > /dev/null
Connection from 10.77.24.17 50821 received!
So yes I admit it's not constantly 900Mbps++, but I'm not that far anyway...