From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans-Christian Armingeon Subject: Re: arp during live migration Date: Wed, 30 Jan 2008 12:17:50 +0100 Message-ID: <47A05CDE.8010601@wh-netz.de> References: 45E88EEA.4020707@dcs.gla.ac.uk <342BAC0A5467384983B586A6B0B3767104DC3DAF@EXNA.corp.stratus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <342BAC0A5467384983B586A6B0B3767104DC3DAF@EXNA.corp.stratus.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: xen-devel@lists.xensource.com Cc: "Graham, Simon" , zamf@dcs.gla.ac.uk List-Id: xen-devel@lists.xenproject.org Graham, Simon wrote: >> I am having some trouble with the send_fake_arp in the netfront >> > driver. > > > Interesting - I was just composing an almost identical note; we've been > seeing some horrible network blackouts in migration that are caused by a > failure to send the gratuitous ARP (blackouts vary from 0-50+ seconds > when the domain is idle and just being pinged from outside). > I am having the same troubles with xen 3.1 from ubuntu gutsy. I have xen-hypervisor-3.1.0-0ubuntu18 instaled on my system. maybe this bug has eben re-introduced? Can somebody confirm, that this is still working? I am currently doing a semester thesis in measuring downtime, while migrating over loaded/lagged links. The goal would be trying to measure/estimate the migrationtime/downtime. I see no ping reply packets, even if the domain is already up and running. It sakes about 10 seconsd, until I see any ping reply packets. Hans-Christian > In my case, I NEVER see the gratuitous ARP being sent (confirmed using > tcpdump on peth0 in Dom0) and the return value from dev_queue_xmit is > sometimes 0 and sometimes 2 (that's PLUS 2 -- congestion notification > [NET_XMIT_CN]). > > My next step was going to be to add instrumentation to netback but I > thought I would ask if this is a known issue with 3.0.3 first... > > Simon > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel >