Am Samstag, den 06.09.2008, 14:26 +0200 schrieb richard lucassen: > On Sat, 06 Sep 2008 14:04:30 +0200 > Fabian Deutsch <[EMAIL PROTECTED]> wrote: > > > Am Samstag, den 06.09.2008, 09:40 +0200 schrieb Christian Borntraeger: > > > Am Montag, 1. September 2008 schrieb Fabian Deutsch: > > > > Hey. > > > > > > > > I'm observing some network problems when using virtio and a tap > > > > if. The trouble is a drop of network troughput from abot 90Mbit/s > > > > to > > about > > > 90kbit/s, > > > > after about 1.7 TB of transferred data. > > > > > > > > Setup > > > > Host: > > > > - Fedora 8, nearly all updates > > > > - Intel(R) Xeon(R) CPU X3210 @ 2.13GHz > > > > - 8GB RAM > > > > - 2 Guests > > > > > > > > Guest: > > > > - Fedora 9 all updates > > > > - virtio nic using tap > > > > - samba sharing a mountpoint using an iscsi target > > > > > > Can you tell us what host kernel and what guest kernel you are > > > using? > > The were > > > some changes to tun/tap for virtio lately which could make a > > difference. > > > > Host: > > Fedora 8 x86_64 > > 2.6.25.14-69.fc8 SMP > > kvm-72 > > > > Guest: > > Fedora 9 i386 > > 2.6.25.11-97.fc9.i686 > > I noticed the same behaviour using a rtl8139 and a tap device. After > some MB's (!) I had to invoke a in the guest: > > ifdown eth0; ifup eth0
ifdown ; ifup doesn't help in this case. Even a guest-restart "init 6" doesn't help. Just shutting it completely down "init 0" and powering it on again helps. > > to get the network back again. I replaced the rtl-8139 by a virtio > device and the problem seems to have gone, but I haven't tried yet with > a large amount of data. Virtio net works fast and withouth trouble - up to some point, then packet loss occurs. > > kvm-73 (kvm74 gives compile errors) > host: 64bit ubuntu-8.04-LTS with vanilla kernel 2.6.26.3 SMP > guest: ubuntu-8.04-LTS with ubuntu kernel 32-bit > > On the same host runs a 32bit w2k3 (virtio NIC) and I haven't noticed > such problems, even when this host ran with an rtl-8139 device. > > Sorry if I missed some postings concerning the issue, I just > (re)subscribed to the list. > > R. > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
