Dear Xen Community, I''m using Xen to virtualize some Windows and Linux servers. Currently I''m using two machines, one for production, which runs Xen 3.2.1 with Debian5 Dom0 and the second one (Xen 4.0.1, openSuse 11.4 dom0) for development/testing. I''m experiencing some problems with an HVM linux domU over the development machine. In particular, the linux domU runs network services (web server, ssh), and, periodically, in an intermittent manner, the domU''s network goes off. I realized that the vnc console attached to the domU still works, i.e., the domU is responsive, while the network doesn''t work. The host machine is underloaded, i.e., it runs just two hvm domUs (the linux domU and an idle windows domU) and is configured in this way: one Intel processor with 4 cores, dom0 with 1 vcpu pinned to core 0 other domains with 1 vcpu pinned to cores 1-3 changing the dom0 credit scheduler configurations doesn''t change this behaviour (e.g., assigning to dom0 a weight of 2048 while other domains have weight set to 256). Any suggestion on how I can solve this problem, or how can I figure out WHERE is the problem? Thanks, Roberto -- Roberto Bifulco, Ph.D. Student robertobifulco.it COMICS Lab - www.comics.unina.it _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Thu, May 5, 2011 at 8:17 AM, Roberto Bifulco <roberto.bifulco2@unina.it> wrote:> Dear Xen Community, > I''m using Xen to virtualize some Windows and Linux servers. > Currently I''m using two machines, one for production, which runs Xen 3.2.1 > with Debian5 Dom0 and the second one (Xen 4.0.1, openSuse 11.4 dom0) for > development/testing. > I''m experiencing some problems with an HVM linux domU over the development > machine. > In particular, the linux domU runs network services (web server, ssh), and, > periodically, in an intermittent manner, the domU''s network goes off. > I realized that the vnc console attached to the domU still works, i.e., the > domU is responsive, while the network doesn''t work. > The host machine is underloaded, i.e., it runs just two hvm domUs (the linux > domU and an idle windows domU) and is configured in this way: > one Intel processor with 4 cores, > dom0 with 1 vcpu pinned to core 0 > other domains with 1 vcpu pinned to cores 1-3 > changing the dom0 credit scheduler configurations doesn''t change this > behaviour (e.g., assigning to dom0 a weight of 2048 while other domains have > weight set to 256). > Any suggestion on how I can solve this problem, or how can I figure out > WHERE is the problem?Have you tried installing the PVonHVM drivers in the Linux domU? Have you tried disabling transmit checksum offloading? Does a linux PV guest have the problem or just HVM? Thanks, Todd> Thanks, > Roberto > -- > Roberto Bifulco, Ph.D. Student > robertobifulco.it > COMICS Lab - www.comics.unina.it > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- Todd Deshane http://www.linkedin.com/in/deshantm http://www.xen.org/products/cloudxen.html http://runningxen.com/ _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Todd, thanks for your fast answer. I''m going to install PVonHVM drivers for the linux domU to give them a try. Today I realized that the intermittent connectivity is an issue only when a second domU is started, i.e, running just the linux domU works well. Anyway, I should solve the issue even in the case of HVM domUs (without PV drivers), so still looking for any hint. Thanks, Roberto 2011/5/5 Todd Deshane <todd.deshane@xen.org>> On Thu, May 5, 2011 at 8:17 AM, Roberto Bifulco > <roberto.bifulco2@unina.it> wrote: > > Dear Xen Community, > > I''m using Xen to virtualize some Windows and Linux servers. > > Currently I''m using two machines, one for production, which runs Xen > 3.2.1 > > with Debian5 Dom0 and the second one (Xen 4.0.1, openSuse 11.4 dom0) for > > development/testing. > > I''m experiencing some problems with an HVM linux domU over the > development > > machine. > > In particular, the linux domU runs network services (web server, ssh), > and, > > periodically, in an intermittent manner, the domU''s network goes off. > > I realized that the vnc console attached to the domU still works, i.e., > the > > domU is responsive, while the network doesn''t work. > > The host machine is underloaded, i.e., it runs just two hvm domUs (the > linux > > domU and an idle windows domU) and is configured in this way: > > one Intel processor with 4 cores, > > dom0 with 1 vcpu pinned to core 0 > > other domains with 1 vcpu pinned to cores 1-3 > > changing the dom0 credit scheduler configurations doesn''t change this > > behaviour (e.g., assigning to dom0 a weight of 2048 while other domains > have > > weight set to 256). > > Any suggestion on how I can solve this problem, or how can I figure out > > WHERE is the problem? > > Have you tried installing the PVonHVM drivers in the Linux domU? > > Have you tried disabling transmit checksum offloading? > > Does a linux PV guest have the problem or just HVM? > > > Thanks, > Todd > > > Thanks, > > Roberto > > -- > > Roberto Bifulco, Ph.D. Student > > robertobifulco.it > > COMICS Lab - www.comics.unina.it > > > > _______________________________________________ > > Xen-users mailing list > > Xen-users@lists.xensource.com > > http://lists.xensource.com/xen-users > > > > > > -- > Todd Deshane > http://www.linkedin.com/in/deshantm > http://www.xen.org/products/cloudxen.html > http://runningxen.com/ > >-- Roberto Bifulco, Ph.D. Student robertobifulco.it COMICS Lab - www.comics.unina.it _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Some more infos! I run a simple ping test from my laptop to both domUs runinng on my server. The ping test shows that both domU suffers intermittent connectivity. More interestingly, when a domU network works, the other domU''s network doesn''t and viceversa. So it seems a "network scheduler" problem. I''m starting searching about how can I customize the behavior of the IO scheduler for VNICs. Roberto 2011/5/6 Roberto Bifulco <roberto.bifulco2@unina.it>> Todd, > thanks for your fast answer. > I''m going to install PVonHVM drivers for the linux domU to give them a try. > Today I realized that the intermittent connectivity is an issue only when a > second domU is started, i.e, running just the linux domU works well. > > Anyway, I should solve the issue even in the case of HVM domUs (without PV > drivers), so still looking for any hint. > Thanks, > Roberto > > 2011/5/5 Todd Deshane <todd.deshane@xen.org> > >> On Thu, May 5, 2011 at 8:17 AM, Roberto Bifulco >> <roberto.bifulco2@unina.it> wrote: >> > Dear Xen Community, >> > I''m using Xen to virtualize some Windows and Linux servers. >> > Currently I''m using two machines, one for production, which runs Xen >> 3.2.1 >> > with Debian5 Dom0 and the second one (Xen 4.0.1, openSuse 11.4 dom0) for >> > development/testing. >> > I''m experiencing some problems with an HVM linux domU over the >> development >> > machine. >> > In particular, the linux domU runs network services (web server, ssh), >> and, >> > periodically, in an intermittent manner, the domU''s network goes off. >> > I realized that the vnc console attached to the domU still works, i.e., >> the >> > domU is responsive, while the network doesn''t work. >> > The host machine is underloaded, i.e., it runs just two hvm domUs (the >> linux >> > domU and an idle windows domU) and is configured in this way: >> > one Intel processor with 4 cores, >> > dom0 with 1 vcpu pinned to core 0 >> > other domains with 1 vcpu pinned to cores 1-3 >> > changing the dom0 credit scheduler configurations doesn''t change this >> > behaviour (e.g., assigning to dom0 a weight of 2048 while other domains >> have >> > weight set to 256). >> > Any suggestion on how I can solve this problem, or how can I figure out >> > WHERE is the problem? >> >> Have you tried installing the PVonHVM drivers in the Linux domU? >> >> Have you tried disabling transmit checksum offloading? >> >> Does a linux PV guest have the problem or just HVM? >> >> >> Thanks, >> Todd >> >> > Thanks, >> > Roberto >> > -- >> > Roberto Bifulco, Ph.D. Student >> > robertobifulco.it >> > COMICS Lab - www.comics.unina.it >> > >> > _______________________________________________ >> > Xen-users mailing list >> > Xen-users@lists.xensource.com >> > http://lists.xensource.com/xen-users >> > >> >> >> >> -- >> Todd Deshane >> http://www.linkedin.com/in/deshantm >> http://www.xen.org/products/cloudxen.html >> http://runningxen.com/ >> >> > > > -- > Roberto Bifulco, Ph.D. Student > robertobifulco.it > COMICS Lab - www.comics.unina.it >-- Roberto Bifulco, Ph.D. Student robertobifulco.it COMICS Lab - www.comics.unina.it _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
You checked the MAC and IP addresses, right? -- Michael South msouth@msouth.org On May 6, 2011, at 12:38, Roberto Bifulco <roberto.bifulco2@unina.it> wrote:> Some more infos! > I run a simple ping test from my laptop to both domUs runinng on my server. The ping test shows that both domU suffers intermittent connectivity. More interestingly, when a domU network works, the other domU''s network doesn''t and viceversa. > So it seems a "network scheduler" problem. > > I''m starting searching about how can I customize the behavior of the IO scheduler for VNICs. > Roberto > > 2011/5/6 Roberto Bifulco <roberto.bifulco2@unina.it> > Todd, > thanks for your fast answer. > I''m going to install PVonHVM drivers for the linux domU to give them a try. > Today I realized that the intermittent connectivity is an issue only when a second domU is started, i.e, running just the linux domU works well. > > Anyway, I should solve the issue even in the case of HVM domUs (without PV drivers), so still looking for any hint. > Thanks, > Roberto > > 2011/5/5 Todd Deshane <todd.deshane@xen.org> > On Thu, May 5, 2011 at 8:17 AM, Roberto Bifulco > <roberto.bifulco2@unina.it> wrote: > > Dear Xen Community, > > I''m using Xen to virtualize some Windows and Linux servers. > > Currently I''m using two machines, one for production, which runs Xen 3.2.1 > > with Debian5 Dom0 and the second one (Xen 4.0.1, openSuse 11.4 dom0) for > > development/testing. > > I''m experiencing some problems with an HVM linux domU over the development > > machine. > > In particular, the linux domU runs network services (web server, ssh), and, > > periodically, in an intermittent manner, the domU''s network goes off. > > I realized that the vnc console attached to the domU still works, i.e., the > > domU is responsive, while the network doesn''t work. > > The host machine is underloaded, i.e., it runs just two hvm domUs (the linux > > domU and an idle windows domU) and is configured in this way: > > one Intel processor with 4 cores, > > dom0 with 1 vcpu pinned to core 0 > > other domains with 1 vcpu pinned to cores 1-3 > > changing the dom0 credit scheduler configurations doesn''t change this > > behaviour (e.g., assigning to dom0 a weight of 2048 while other domains have > > weight set to 256). > > Any suggestion on how I can solve this problem, or how can I figure out > > WHERE is the problem? > > Have you tried installing the PVonHVM drivers in the Linux domU? > > Have you tried disabling transmit checksum offloading? > > Does a linux PV guest have the problem or just HVM? > > > Thanks, > Todd > > > Thanks, > > Roberto > > -- > > Roberto Bifulco, Ph.D. Student > > robertobifulco.it > > COMICS Lab - www.comics.unina.it > > > > _______________________________________________ > > Xen-users mailing list > > Xen-users@lists.xensource.com > > http://lists.xensource.com/xen-users > > > > > > -- > Todd Deshane > http://www.linkedin.com/in/deshantm > http://www.xen.org/products/cloudxen.html > http://runningxen.com/ > > > > > -- > Roberto Bifulco, Ph.D. Student > robertobifulco.it > COMICS Lab - www.comics.unina.it > > > > -- > Roberto Bifulco, Ph.D. Student > robertobifulco.it > COMICS Lab - www.comics.unina.it > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On 05/10/2011 03:17 AM, Michael South wrote:> You checked the MAC and IP addresses, right? > > -- > Michael South > msouth@msouth.org <mailto:msouth@msouth.org>Thanks a lot for that question! I just had the same problem: While setting up a new debian domU I was wondering why the network was so slow just on that vm. I noticed that there was a burst of traffic every now and then. First I thought - like Roberto - it was a scheduling problem. But your comment caused me to check the MAC address of that machine and it was in fact the same like on another vm *silly me*.> > On May 6, 2011, at 12:38, Roberto Bifulco <roberto.bifulco2@unina.it > <mailto:roberto.bifulco2@unina.it>> wrote: > >> Some more infos! >> I run a simple ping test from my laptop to both domUs runinng on my >> server. The ping test shows that both domU suffers intermittent >> connectivity. More interestingly, when a domU network works, the other >> domU''s network doesn''t and viceversa. >> So it seems a "network scheduler" problem. >> >> I''m starting searching about how can I customize the behavior of the >> IO scheduler for VNICs. >> Roberto >>-- Mark Dokter - System Administrator Institute for Computergraphics and Vision - http://www.icg.tugraz.at Graz University of Technology, Inffeldgasse 16/II, 8010 Graz, Austria Phone: +43/316/873-5036, Fax: +43/316/873-5050 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
I feel a little bit stupid :-) I assumed that no MAC was specified in the domUs config file but actually I didn''t verified that... It was the case! Shame on me! Thanks for the support Roberto 2011/5/10 Michael South <msouth@msouth.org>> You checked the MAC and IP addresses, right? > > -- > Michael South > msouth@msouth.org > > On May 6, 2011, at 12:38, Roberto Bifulco <roberto.bifulco2@unina.it> > wrote: > > Some more infos! > I run a simple ping test from my laptop to both domUs runinng on my server. > The ping test shows that both domU suffers intermittent connectivity. More > interestingly, when a domU network works, the other domU''s network doesn''t > and viceversa. > So it seems a "network scheduler" problem. > > I''m starting searching about how can I customize the behavior of the IO > scheduler for VNICs. > Roberto > > 2011/5/6 Roberto Bifulco < <roberto.bifulco2@unina.it> > roberto.bifulco2@unina.it> > >> Todd, >> thanks for your fast answer. >> I''m going to install PVonHVM drivers for the linux domU to give them a >> try. >> Today I realized that the intermittent connectivity is an issue only when >> a second domU is started, i.e, running just the linux domU works well. >> >> Anyway, I should solve the issue even in the case of HVM domUs (without PV >> drivers), so still looking for any hint. >> Thanks, >> Roberto >> >> 2011/5/5 Todd Deshane < <todd.deshane@xen.org>todd.deshane@xen.org> >> >>> On Thu, May 5, 2011 at 8:17 AM, Roberto Bifulco >>> < <roberto.bifulco2@unina.it>roberto.bifulco2@unina.it> wrote: >>> > Dear Xen Community, >>> > I''m using Xen to virtualize some Windows and Linux servers. >>> > Currently I''m using two machines, one for production, which runs Xen >>> 3.2.1 >>> > with Debian5 Dom0 and the second one (Xen 4.0.1, openSuse 11.4 dom0) >>> for >>> > development/testing. >>> > I''m experiencing some problems with an HVM linux domU over the >>> development >>> > machine. >>> > In particular, the linux domU runs network services (web server, ssh), >>> and, >>> > periodically, in an intermittent manner, the domU''s network goes off. >>> > I realized that the vnc console attached to the domU still works, i.e., >>> the >>> > domU is responsive, while the network doesn''t work. >>> > The host machine is underloaded, i.e., it runs just two hvm domUs (the >>> linux >>> > domU and an idle windows domU) and is configured in this way: >>> > one Intel processor with 4 cores, >>> > dom0 with 1 vcpu pinned to core 0 >>> > other domains with 1 vcpu pinned to cores 1-3 >>> > changing the dom0 credit scheduler configurations doesn''t change this >>> > behaviour (e.g., assigning to dom0 a weight of 2048 while other domains >>> have >>> > weight set to 256). >>> > Any suggestion on how I can solve this problem, or how can I figure out >>> > WHERE is the problem? >>> >>> Have you tried installing the PVonHVM drivers in the Linux domU? >>> >>> Have you tried disabling transmit checksum offloading? >>> >>> Does a linux PV guest have the problem or just HVM? >>> >>> >>> Thanks, >>> Todd >>> >>> > Thanks, >>> > Roberto >>> > -- >>> > Roberto Bifulco, Ph.D. Student >>> > <http://robertobifulco.it>robertobifulco.it >>> > COMICS Lab - <http://www.comics.unina.it>www.comics.unina.it >>> > >>> > _______________________________________________ >>> > Xen-users mailing list >>> > <Xen-users@lists.xensource.com>Xen-users@lists.xensource.com >>> > <http://lists.xensource.com/xen-users> >>> http://lists.xensource.com/xen-users >>> > >>> >>> >>> >>> -- >>> Todd Deshane >>> <http://www.linkedin.com/in/deshantm> >>> http://www.linkedin.com/in/deshantm >>> <http://www.xen.org/products/cloudxen.html> >>> http://www.xen.org/products/cloudxen.html >>> <http://runningxen.com/>http://runningxen.com/ >>> >>> >> >> >> -- >> Roberto Bifulco, Ph.D. Student >> <http://robertobifulco.it>robertobifulco.it >> COMICS Lab - <http://www.comics.unina.it>www.comics.unina.it >> > > > > -- > Roberto Bifulco, Ph.D. Student > <http://robertobifulco.it>robertobifulco.it > COMICS Lab - <http://www.comics.unina.it>www.comics.unina.it > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > >-- Roberto Bifulco, Ph.D. Student robertobifulco.it COMICS Lab - www.comics.unina.it _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users