Messages in this thread | | | Date | Thu, 26 Apr 2012 15:53:43 +0200 | Subject | Re: many rx packets dropped since 2.6.37 | From | Chris <> |
| |
2012/4/25 Eric Dumazet <eric.dumazet@gmail.com>: > On Wed, 2012-04-25 at 16:38 +0200, Chris wrote: >> 2012/4/25 Eric Dumazet <eric.dumazet@gmail.com>: >> >> Why do we see dropped packets only in virtual environments and bonded >> >> network interfaces and not on real network interfaces? >> > >> > This has to be investigated, eventually. >> >> Do you have the opportunity to test it? Just install fedora 16 (linux >> 3.3) or ubuntu 12.04 (linux 3.2) as guest under kvm and use as virtual >> network card virtio_net or e1000. >> >> You will see many lost rx packets and i have no idea why??? > > > You can use drop_monitor / dropwatch to figure out > > https://fedorahosted.org/dropwatch/ > > http://prefetch.net/blog/index.php/2011/07/11/using-netstat-and-dropwatch-to-observe-packet-loss-on-linux-servers/
Hello Eric,
Okay this is a Fedora-16 VM under KVM with 4 minutes uptime only and dropwatch!
349 dropped packets in 4 minutes uptime??
[root@test ~]# uname -r 3.3.2-6.fc16.x86_64 [root@test ~]# dropwatch -l kas Initalizing kallsyms db dropwatch> start Enabling monitoring... Kernel monitoring activated. Issue Ctrl-C to stop monitoring 1 drops at netlink_unicast+1bc 3 drops at ip_rcv_finish+f0 1 drops at __netif_receive_skb+583 1 drops at ip_rcv+d3 9 drops at ip_rcv_finish+f0 9 drops at ip_rcv_finish+f0 1 drops at __netif_receive_skb+583 6 drops at ip_rcv_finish+f0 1 drops at nf_hook_slow+12b 4 drops at ip_rcv_finish+f0 1 drops at __netif_receive_skb+583 4 drops at ip_rcv_finish+f0 1 drops at nf_hook_slow+12b 3 drops at ip_rcv_finish+f0 3 drops at nf_hook_slow+12b 2 drops at __netif_receive_skb+583 1 drops at ip6_mc_input+1f6 7 drops at ip_rcv_finish+f0 1 drops at ip_rcv_finish+f0 1 drops at netlink_unicast+1bc 1 drops at skb_queue_purge+20 2 drops at __netif_receive_skb+583 1 drops at ip_rcv_finish+f0 1 drops at nf_hook_slow+12b 1 drops at ip_rcv_finish+f0 1 drops at __netif_receive_skb+583 19 drops at ip_rcv+d3 2 drops at ip_rcv_finish+f0 37 drops at ip_rcv+d3 2 drops at __netif_receive_skb+583 43 drops at ip_rcv+d3 5 drops at ip_rcv_finish+f0 1 drops at __netif_receive_skb+583 1 drops at nf_hook_slow+12b 1 drops at ip6_mc_input+1f6 7 drops at ip_rcv_finish+f0 39 drops at ip_rcv+d3 2 drops at ip6_mc_input+1f6 1 drops at netlink_unicast+1bc 1 drops at skb_queue_purge+20 29 drops at ip_rcv+d3 7 drops at ip_rcv_finish+f0 2 drops at __netif_receive_skb+583 2 drops at ip6_mc_input+1f6 54 drops at ip_rcv+d3 3 drops at __netif_receive_skb+583 2 drops at nf_hook_slow+12b 3 drops at ip_rcv_finish+f0 1 drops at ip6_mc_input+1f6 36 drops at ip_rcv+d3 6 drops at ip_rcv_finish+f0 2 drops at __netif_receive_skb+583 1 drops at nf_hook_slow+12b 1 drops at icmpv6_rcv+305 37 drops at ip_rcv+d3 1 drops at __netif_receive_skb+583 2 drops at ip_rcv_finish+f0 4 drops at ip_rcv_finish+f0 39 drops at ip_rcv+d3 2 drops at __netif_receive_skb+583 1 drops at netlink_unicast+1bc 1 drops at skb_queue_purge+20 1 drops at nf_hook_slow+12b 38 drops at ip_rcv+d3 3 drops at __netif_receive_skb+583 2 drops at ip6_mc_input+1f6 1 drops at ip_rcv_finish+f0 46 drops at ip_rcv+d3 1 drops at __netif_receive_skb+583 1 drops at ip_rcv_finish+f0 ^CGot a stop message dropwatch> exit Shutting down ... [root@test ~]# ifconfig | grep dropped RX packets:161562 errors:0 dropped:349 overruns:0 frame:0 TX packets:2140 errors:0 dropped:0 overruns:0 carrier:0 RX packets:4 errors:0 dropped:0 overruns:0 frame:0 TX packets:4 errors:0 dropped:0 overruns:0 carrier:0 [root@test ~]# uptime 15:47:00 up 4 min, 3 users, load average: 0.01, 0.04, 0.03 [root@test ~]# netstat -s Ip: 1553 total packets received 610 with invalid addresses 0 forwarded 0 incoming packets discarded 345 incoming packets delivered 478 requests sent out 71 dropped because of missing route Icmp: 4 ICMP messages received 0 input ICMP message failed. ICMP input histogram: echo requests: 2 echo replies: 2 4 ICMP messages sent 0 ICMP messages failed ICMP output histogram: echo request: 2 echo replies: 2 IcmpMsg: InType0: 2 InType8: 2 OutType0: 2 OutType8: 2 Tcp: 1 active connections openings 2 passive connection openings 0 failed connection attempts 0 connection resets received 2 connections established 2353 segments received 2096 segments send out 0 segments retransmited 0 bad segments received. 0 resets sent Udp: 51 packets received 0 packets to unknown port received. 0 packet receive errors 51 packets sent 0 receive buffer errors 0 send buffer errors UdpLite: TcpExt: 1 TCP sockets finished time wait in fast timer 3 delayed acks sent 2 packets directly queued to recvmsg prequeue. 2 packets directly received from prequeue 2009 packets header predicted 165 acknowledgments not containing data received IPReversePathFilter: 82 IpExt: InMcastPkts: 13 InBcastPkts: 60 InOctets: 146431 OutOctets: 63310 InMcastOctets: 416 InBcastOctets: 12060
-- Chris
| |