From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Reese Faucette" Subject: vif interface dropping 80% packets Date: Mon, 5 Feb 2007 16:30:51 -0800 Message-ID: <086c01c74986$0e8fd120$58c31fac@bart> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1700512473==" Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Mime-version: 1.0 Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org This is a multi-part message in MIME format. --===============1700512473== Content-Type: multipart/alternative; boundary="----=_NextPart_000_0869_01C74943.0027E700" This is a multi-part message in MIME format. ------=_NextPart_000_0869_01C74943.0027E700 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I'm trying to characterize the performance of 10G ethernet to a user = domain. =20 The machine has 2 configured ethernet cards, eth0 is a 1G card, and eth2 = is a 10G card. (eth1 is another 1G card and eth3 is another 10G, but = these are not configured) I have network bridge set up on eth2 with defaults, nothing special, = just: /etc/xen/scripts/network-bridge start vifnum=3D2 I have a user domain that attaches eth1 to this vif, and when I try = netperf tests, I get tons of packet loss in the vif interface. vif3.1 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link UP BROADCAST RUNNING NOARP MTU:1500 Metric:1 RX packets:165602 errors:0 dropped:0 overruns:0 frame:0 TX packets:12982847 errors:0 dropped:48987465 overruns:0 = carrier:0 collisions:0 txqueuelen:0 RX bytes:8679444 (8.2 MiB) TX bytes:20888548648 (19.4 GiB) As can be seen above, vif3.1 drops about 80% of the packets it should = transmit. Is this expected due to something in the dom0 -> domU = interface just not being able to keep up, or is there something I can do = about it? It almost looks like the dom0->domU link is throttled at = about 1Gb/s. I say this because the 10G link is running about 50-60% = capacity when the drop rate is 80%. Everything has MTU 1500, btw - I noticed that Xen is pretty unhappy with = an MTU of 9000. thanks, -reese ------=_NextPart_000_0869_01C74943.0027E700 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I'm trying to characterize the = performance of 10G=20 ethernet to a user domain.

The machine has 2 configured ethernet = cards, eth0=20 is a 1G card, and eth2 is a 10G card. (eth1 is another 1G card and = eth3 is=20 another 10G, but these are not configured)

I have network bridge set up on eth2 = with defaults,=20 nothing special, just:

= /etc/xen/scripts/network-bridge start=20 vifnum=3D2

I have a user domain that attaches eth1 = to this=20 vif, and when I try netperf tests, I get tons of packet loss in the vif=20 interface.

vif3.1    Link = encap:Ethernet =20 HWaddr=20 FE:FF:FF:FF:FF:FF
        &nbs= p;=20 inet6 addr: fe80::fcff:ffff:feff:ffff/64=20 Scope:Link
          UP=20 BROADCAST RUNNING NOARP MTU:1500 =20 Metric:1
          RX=20 packets:165602 errors:0 dropped:0 overruns:0=20 frame:0
          TX=20 packets:12982847 errors:0 dropped:48987465 overruns:0=20 carrier:0
          = collisions:0=20 txqueuelen:0
          = RX=20 bytes:8679444 (8.2 MiB) TX bytes:20888548648 (19.4 = GiB)

As can be seen above, vif3.1 drops = about 80% of the=20 packets it should transmit. Is this expected due to something in = the dom0=20 -> domU interface just not being able to keep up, or is there = something I can=20 do about it? It almost looks like the dom0->domU link is = throttled at=20 about 1Gb/s. I say this because the 10G link is running about = 50-60%=20 capacity when the drop rate is 80%.

Everything has MTU 1500, btw - I = noticed that Xen=20 is pretty unhappy with an MTU of 9000.

thanks,

-reese

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