sorry forgot to change the subject of this email. Hi all I am using xen-3.4.1 with PV OS kernel 2.6.31.4 in FC11. When ever I try using a guest as web server to fetch its data from different nodes I dont experience enough speed even using 1G link on both sides. After running different bench marks I have come to know that while using guest as a sender on 1G link throughput goes down. #wget http://10.11.21.113/VTS_04_1.VOB --2009-11-19 15:17:17-- http://10.11.21.113/VTS_04_1.VOB Connecting to 10.11.21.113:80... connected. HTTP request sent, awaiting response... 200 OK Length: 1073739776 (1024M) [text/plain] Saving to: `VTS_04_1.VOB'' 0% [ ] 432,670 14.7K/s eta 13h 51m ^C here are some results i have collected using iperf. Guest sending data to an external system [root@fasiha fasiha]# iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 4] local 10.11.20.223 port 5001 connected with 10.11.21.113 port 50284 [ ID] Interval Transfer Bandwidth [ 4] 0.0-31.8 sec 952 KBytes 245 Kbits/sec [root@F11-G3S1 ~]# iperf -c 10.11.20.223 -t 30 ------------------------------------------------------------ Client connecting to 10.11.20.223, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 10.11.21.113 port 50284 connected with 10.11.20.223 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-30.2 sec 952 KBytes 259 Kbits/sec Guest receiving data from external system [root@F11-G3S1 ~]# iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 4] local 10.11.21.113 port 5001 connected with 10.11.20.223 port 40423 [ ID] Interval Transfer Bandwidth [ 4] 0.0-30.0 sec 3.27 GBytes 937 Mbits/sec [root@fasiha fasiha]# iperf -c 10.11.21.113 -t 30 ------------------------------------------------------------ Client connecting to 10.11.21.113, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 10.11.20.223 port 40423 connected with 10.11.21.113 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-30.0 sec 3.27 GBytes 937 Mbits/sec It should be the same or comparable in both cases. What could be the reason? Regards, Fasiha Ashraf The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. http://in.yahoo.com/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel