I upgraded one of my servers today from Xen 2.0.6 to Xen 3. With Xen 2, I experienced network dropouts from time to time, usually once or twice a day, where all domU network activity would stop for up to 15 minutes. With Xen 3, I am experiencing horrible latency almost all of the time. CPU utilization (from ''xm top'') is as close to zero as it gets, yet I get erratic ping results like this between domU and dom0 or any other networked machine. See a 30-second snapshot: $ ping 192.168.1.144 PING 192.168.1.144 (192.168.1.144) 56(84) bytes of data. 64 bytes from 192.168.1.144: icmp_seq=1 ttl=64 time=19.6 ms 64 bytes from 192.168.1.144: icmp_seq=2 ttl=64 time=171 ms 64 bytes from 192.168.1.144: icmp_seq=3 ttl=64 time=322 ms 64 bytes from 192.168.1.144: icmp_seq=4 ttl=64 time=482 ms 64 bytes from 192.168.1.144: icmp_seq=5 ttl=64 time=61.9 ms 64 bytes from 192.168.1.144: icmp_seq=6 ttl=64 time=227 ms 64 bytes from 192.168.1.144: icmp_seq=7 ttl=64 time=391 ms 64 bytes from 192.168.1.144: icmp_seq=8 ttl=64 time=547 ms 64 bytes from 192.168.1.144: icmp_seq=9 ttl=64 time=118 ms 64 bytes from 192.168.1.144: icmp_seq=10 ttl=64 time=122 ms 64 bytes from 192.168.1.144: icmp_seq=11 ttl=64 time=293 ms 64 bytes from 192.168.1.144: icmp_seq=12 ttl=64 time=455 ms 64 bytes from 192.168.1.144: icmp_seq=13 ttl=64 time=49.4 ms 64 bytes from 192.168.1.144: icmp_seq=14 ttl=64 time=220 ms 64 bytes from 192.168.1.144: icmp_seq=15 ttl=64 time=567 ms 64 bytes from 192.168.1.144: icmp_seq=16 ttl=64 time=169 ms 64 bytes from 192.168.1.144: icmp_seq=17 ttl=64 time=0.305 ms 64 bytes from 192.168.1.144: icmp_seq=18 ttl=64 time=0.292 ms 64 bytes from 192.168.1.144: icmp_seq=19 ttl=64 time=0.277 ms 64 bytes from 192.168.1.144: icmp_seq=20 ttl=64 time=0.271 ms 64 bytes from 192.168.1.144: icmp_seq=21 ttl=64 time=0.276 ms 64 bytes from 192.168.1.144: icmp_seq=22 ttl=64 time=0.280 ms 64 bytes from 192.168.1.144: icmp_seq=23 ttl=64 time=0.662 ms 64 bytes from 192.168.1.144: icmp_seq=24 ttl=64 time=0.277 ms 64 bytes from 192.168.1.144: icmp_seq=25 ttl=64 time=0.265 ms 64 bytes from 192.168.1.144: icmp_seq=26 ttl=64 time=0.264 ms 64 bytes from 192.168.1.144: icmp_seq=27 ttl=64 time=0.273 ms 64 bytes from 192.168.1.144: icmp_seq=28 ttl=64 time=168 ms 64 bytes from 192.168.1.144: icmp_seq=29 ttl=64 time=93.3 ms 64 bytes from 192.168.1.144: icmp_seq=30 ttl=64 time=379 ms --- 192.168.1.144 ping statistics --- 31 packets transmitted, 30 received, 3% packet loss, time 30011ms rtt min/avg/max/mdev = 0.264/162.221/567.720/181.810 ms Notice that it''s fine for 10 seconds and then goes to hell again. I have seen ping times exceeding 1000ms on a routine basis. dom0 network performance is absolutely normal. Any suggestions? I am pulling my hair out. I tried running fewer domU''s (normally I run 11) and it seems to make no difference. I have tried SMP and non-SMP, with no difference. Hardware is 2 x Athlon MP 1800+ on a Tyan Tiger MPX motherboard. 3.5G RAM. 3ware disk controller and 3com 3c59x network. Thanks Jeff _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users