From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Venefax" Subject: RE: xen.git branch reorg Date: Sat, 25 Apr 2009 03:03:28 -0400 Message-ID: <0a4301c9c573$f1029900$d307cb00$@com> References: <1240612762.1918.5.camel@leto.intern.saout.de> <724403.69764.qm@web56102.mail.re3.yahoo.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0923883457==" Return-path: In-Reply-To: <724403.69764.qm@web56102.mail.re3.yahoo.com> Content-Language: en-us List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: bderzhavets@yahoo.com, 'Jeremy Fitzhardinge' , 'Christophe Saout' Cc: 'Xen-devel' , 'Ian Campbell' List-Id: xen-devel@lists.xenproject.org This is a multipart message in MIME format. --===============0923883457== Content-Type: multipart/alternative; boundary="----=_NextPart_000_0A44_01C9C552.69F0F900" Content-Language: en-us This is a multipart message in MIME format. ------=_NextPart_000_0A44_01C9C552.69F0F900 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit What are the exact commands to turn off Segmentation Offload and Checksum Offload? Also, should this be done only at Dom0 or also at DomU's? Is this correct or should it be "eth0"? /usr/local/sbin/ethtool -K etho tx off F.Alves 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 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 Gigabit Ethernet driver (ASUS P5KR) . I gonna try it at DomUs at my earliest convenience. Boris. --- On Fri, 4/24/09, Christophe Saout wrote: 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 Hi Jeremy, > > In meantime time i see, that 2.6.30-rc3&rc2&rc1-tip are affected. > > Solution is the same as on Solaris xVM Linux DomUs about one > > year ago - is to disable checksum (nothing else) offloading at Linux > > DomUs ( CentOS 5.3, Ubuntu 9.04) > > > > /usr/local/sbin/ethtool -K etho tx off > > OK, that's a good lead. 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. 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 "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. 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 ------=_NextPart_000_0A44_01C9C552.69F0F900 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

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

Also, should this be done only at Dom0 or also at = DomU’s?

Is this correct or should it be = “eth0”?

/usr/local/sbin/ethtool -K etho tx = off

F.Alves

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

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 = Gigabit
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:

From: Christophe = Saout <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

Hi Jeremy,

  

> >  In meantime time i see,  that

 =
2.6.30-rc3&rc2&rc1-tip are

affected.

> > Solution is the same as on Solaris xVM Linux DomUs about =
one

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

Linux 

> > DomUs ( CentOS 5.3, Ubuntu 9.04)

> >

> > /usr/local/sbin/ethtool -K etho tx off

>

> OK, that's a good lead.

  

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.

  

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

"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.

  

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

        =
Christophe

  

  

  

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Xen-devel mailing list

Xen-devel@lists.xensource.com

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

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