From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Derzhavets Subject: RE: xen.git branch reorg Date: Sat, 25 Apr 2009 01:35:25 -0700 (PDT) Message-ID: <462898.6776.qm@web56104.mail.re3.yahoo.com> References: <0a4301c9c573$f1029900$d307cb00$@com> Reply-To: bderzhavets@yahoo.com Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0021155111==" Return-path: In-Reply-To: <0a4301c9c573$f1029900$d307cb00$@com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Venefax Cc: 'Xen-devel' List-Id: xen-devel@lists.xenproject.org --===============0021155111== Content-Type: multipart/alternative; boundary="0-378318572-1240648525=:6776" --0-378318572-1240648525=:6776 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable I tried at DomU: 1. Specifies whether TX checksumming should be disabled. # /usr/local/sbin/ethtool -K eth0 tx off 2. Specifies whether TCP segmentation offload should be disabled. # /usr/local/sbin/ethtool -K eth0 tso off 3.=C2=A0 Specifies whether UDP fragmentation offload should be disabled # /usr/local/sbin/ethtool -K eth0 ufo off Second parameter is your Ethernet interface . Might be eth1 or eth2. Just install ethtool-6 to get=C2=A0 " man ethtool " handy You can try all of them, just first , second and third. Whatever provide a relief. I had to run second to brought up VNC on CentOS 5.2 Dom0=20 =C2=A0(on bare metal ASUS P5KR) I believe Linux driver for Atansic Gigabit Ethernet is not good. Regarding DomU access from from the Net and vice versa usually first one helps (at DomU ).=20 I don't know what exactly Chris did. "gso" option fails. Some network education is obviously required for myself at least ;) To read and understand tcpdump's captured logs for instance. Boris. --- On Sat, 4/25/09, Venefax wrote: From: Venefax Subject: RE: [Xen-devel] xen.git branch reorg To: bderzhavets@yahoo.com, "'Jeremy Fitzhardinge'" , "'Chr= istophe Saout'" Cc: "'Xen-devel'" , "'Ian Campbell'" Date: Saturday, April 25, 2009, 3:03 AM =20 =20 What are the exact commands to turn off Segmentation Offload and Checksum Offload?=20 Also, should this be done only at Dom0 or also at DomU=E2=80=99s?=20 Is this correct or should it be =E2=80=9Ceth0=E2=80=9D?=20 =C2=A0=20 /usr/local/sbin/ethtool -K etho tx off=20 F.Alves=20 From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Boris Derzhavets Sent: Saturday, April 25, 2009 2:55 AM To: Jeremy Fitzhardinge; Christophe Saout Cc: Xen-devel; Ian Campbell Subject: Re: [Xen-devel] xen.git branch reorg=20 =C2=A0=20 =20 =20 Chris, =20 I have to apologize. Turning off segmentation offloading may work as well= . Just now it fixed VNC issue on bare metal - CentOS 5.2 with Atansic Gigab= it Ethernet driver (ASUS P5KR) . I gonna try it at DomUs at my earliest convenience. =20 Boris. =20 --- On Fri, 4/24/09, Christophe Saout wrote:=20 From: Christophe Saout Subject: Re: [Xen-devel] xen.git branch reorg To: "Jeremy Fitzhardinge" Cc: bderzhavets@yahoo.com, "Xen-devel" , "Ian Campbell" Date: Friday, April 24, 2009, 6:39 PM=20 Hi Jeremy, =20 > >=C2=A0 In meantime time i see,=C2=A0 that 2.6.30-rc3&rc2&rc1-tip are affected. > > Solution is the same as on Solaris xVM Linux DomUs about one > > year ago -=C2=A0 is=C2=A0 to disable checksum (nothing else) offloading= at Linux=20 > > DomUs ( CentOS 5.3, Ubuntu 9.04) > > > > /usr/local/sbin/ethtool -K etho tx off > > OK, that's a good lead. =20 Yes, I've been seeing this too (and meant to investigate it before claiming there's abug) and I can confirm that turning off segmentation offloading "cures" the problem here too. =20 Now the tcpdump on Dom0 looks interesting.=C2=A0 It repeatedly sees a packe= t with 2880 byte from DomU coming in, which is then dropped and ICMP "fragmentation needed" sent back, the DomU resends a 1440 byte packet (after some delay), which then goes through, but then the next one is a 2880 byte one again, and so on. =20 FYI: My Dom0 is running NAT, in case this is relevant. =20 =20 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Christophe =20 =20 =20 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel=20 =20 =C2=A0=20 =20 =0A=0A=0A --0-378318572-1240648525=:6776 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
I tried at DomU:

1. Specifies whether = TX checksumming should be disabled.
# /usr/local/sbin/ethtool -K eth0 tx= off

2. Specifies whether TCP segmentation offload should be disable= d.
# /usr/local/sbin/ethtool -K eth0 tso off

3.  Specifies w= hether UDP fragmentation offload should be disabled
# /usr/local/sbin/et= htool -K eth0 ufo off

Second parameter is your Ethernet interface . = Might be eth1 or eth2.
Just install ethtool-6 to get  " man ethtool= " handy
You can try all of them, just first , second and third.
What= ever provide a relief.

I had to run second to brought up VNC on Cent= OS 5.2 Dom0
 (on bare metal ASUS P5KR)
I believe Linux driver f= or Atansic Gigabit Ethernet is not good.
Regarding DomU access from from= the Net and vice versa usually
first one helps (at DomU ).
I don't know what exactly Chris did. "gso" option fails.
Some network education= is obviously required for myself at least ;)
To read and understand tcp= dump's captured logs for instance.

Boris.



--- On S= at, 4/25/09, Venefax <venefax@gmail.com> wrote:
From: Venefax <venefax@gmail.com>
Subject: RE: [= Xen-devel] xen.git branch reorg
To: bderzhavets@yahoo.com, "'Jeremy Fitz= hardinge'" <jeremy@goop.org>, "'Christophe Saout'" <christophe@sao= ut.de>
Cc: "'Xen-devel'" <xen-devel@lists.xensource.com>, "'Ian= Campbell'" <Ian.Campbell@citrix.com>
Date: Saturday, April 25, 20= 09, 3:03 AM

=20 =20

What are the= exact commands to turn off Segmentation Offload and Checksum Offload?

=20

Also, should= this be done only at Dom0 or also at DomU=E2=80=99s?

=20

Is this corr= ect or should it be =E2=80=9Ceth0=E2=80=9D?

=20

 

=20

/usr/local/s= bin/ethtool -K etho tx off

=20

F.Alves

=20

From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Boris Derzhavets
Sent: Saturday, April 25, 2009 2:55 AM
To: Jeremy Fitzhardinge; Christophe Saout
Cc: Xen-devel; Ian Campbell
Subject: Re: [Xen-devel] xen.git branch reorg

=20

 

=20 =20

Chris,

I have to apologize. Turning off segmentation offloading may work as well= .
Just now it fixed VNC issue on bare metal - CentOS 5.2 with Atansic Gigab= it
Ethernet driver (ASUS P5KR) . I gonna try it at DomUs at my earliest convenience.

Boris.

--- On Fri, 4/24/09, Christophe Saout <christophe@saout.de> wrote:

=20

From: Christophe Sa= out <christophe@saout.de>
Subject: Re: [Xen-devel] xen.git branch reorg
To: "Jeremy Fitzhardinge" <jeremy@goop.org>
Cc: bderzhavets@yahoo.com, "Xen-devel" <xen-devel@lists.xensource.com>, "Ian Campbell" <Ian.Campbell@citrix.com>
Date: Friday, April 24, 2009, 6:39 PM

=20 
Hi Jeremy,

  

> >  In meantime time i see,&=
nbsp; that
 2.6.30-rc3&rc2&rc1-tip are

affected.
> > Solution is the same as on Solaris xVM Linux DomUs about on=
e

> > year ago -  is  to disable checksum (nothing e=
lse) offloading at

Linux 

> > DomUs ( CentOS 5.3, Ubunt=
u 9.04)

> >

> > /usr/local/sbin/ethtool -K etho t=
x off

>

> OK, that's a good lead.

  

Yes,=
 I've been seeing this too (and meant to investigate it before

claim=
ing there's abug) and I can confirm that turning off segmentation

of=
floading "cures" the problem here too.

  

Now the tcpdump on =
Dom0 looks interesting.  It repeatedly sees a packet

with 2880 =
byte from DomU coming in, which is then dropped and ICMP

"fragmentat=
ion needed" sent back, the DomU resends a 1440 byte
 packet

(after some delay), which then goes through, but then the ne=
xt one is a

2880 byte one again, and so on.

  

FYI: My=
 Dom0 is running NAT, in case this is relevant.

  

  

=
  
        Christophe

 =
 

  

  

______________________________________________=
_

Xen-devel mailing list

Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

 

=20
=20

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