WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] Vif dropping packets

To: Peter Booth <peter_booth@xxxxxx>
Subject: Re: [Xen-users] Vif dropping packets
From: Mike Lovell <mike@xxxxxxxxxxxx>
Date: Fri, 26 Jun 2009 16:26:57 -0600
Cc: "xen-users@xxxxxxxxxxxxxxxxxxx" <xen-users@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Fri, 26 Jun 2009 15:29:12 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <50146DE0-1127-4B23-B578-C30BD4CD30F6@xxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <4A452DF2.2010307@xxxxxxxxxxxx> <50146DE0-1127-4B23-B578-C30BD4CD30F6@xxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird 2.0.0.22 (X11/20090608)
I'm not entirely sure what you are asking with that second question. sar is installed in the guests. I did `sar -u1 1000` to watch the status for a while. Here is an abbreviated output with the averages and the line I saw with the highest %steal

04:13:12 PM CPU %user %nice %system %iowait %steal %idle 04:13:16 PM all 0.00 0.00 0.00 0.00 0.99 99.01 Average: all 0.01 0.00 0.02 0.55 0.05 99.37

Overall, these vms aren't doing a lot. Mainly sitting idle waiting for a QA engineer to test code functionality. I should probably say a little more about the config. The host boxes are dual quad-core Opteron 2346HE systems with 24GB of memory and a ton of disks. Currently there are 28 virtual machines running on the one I have been checking but most of them idle.

Hope that helps or is what you were looking for.

mike

Peter Booth wrote:
Mike,

You don't say anything about the workload on your system or the resource consumption that it causes.

Do you have sar installed on the domUs? Does a one second vmstat show a %st that's above 1%?

Sent from my iPhone

On Jun 26, 2009, at 4:22 PM, Mike Lovell <mike@xxxxxxxxxxxx> wrote:

I have a problem with packets being dropped on some vif interfaces. I currently have a box running Debian Lenny with Xen 3.2.1. The host is running the Xen-ified kernel from the Debian repos. 2.6.26-1-xen-amd64. The host has a single bridge, 'vmnet', that connects to one physical interface and all of the guest's interfaces connect to. If I do a 'ifconfig vifX.0', I see dropped TX packets. Looking at the guest does not show any dropped packets on its interface.

From the host
# cat /etc/network/interfaces
auto vmnet
iface vmnet inet static
      address 10.135.2.71
      netmask 255.255.255.224
      bridge_ports eth1
      bridge_stp off
      bridge_fd 9
      bridge_hello 2
      bridge_maxage 12


# brctl show vmnet
bridge name    bridge id        STP enabled    interfaces
vmnet               8000.003048c8166d    no        eth1
vif22.0 ... <lots of interfaces>

# ifconfig vif22.0
vif22.0 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link
        UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
        RX packets:7946252 errors:0 dropped:0 overruns:0 frame:0
        TX packets:8282858 errors:0 dropped:160 overruns:0 carrier:0
        collisions:0 txqueuelen:32
        RX bytes:5758663699 (5.3 GiB)  TX bytes:5887860418 (5.4 GiB)


From the guest
# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:16:3E:02:00:91 inet addr:10.135.2.91 Bcast:10.135.2.127 Mask:255.255.255.192
        inet6 addr: fe80::216:3eff:fe02:91/64 Scope:Link
        UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
        RX packets:8283072 errors:0 dropped:0 overruns:0 frame:0
        TX packets:7946364 errors:0 dropped:0 overruns:0 carrier:0
        collisions:0 txqueuelen:1000
        RX bytes:5887884877 (5.4 GiB)  TX bytes:5869927068 (5.4 GiB)

# cat /etc/network/interfaces

auto eth0
iface eth0 inet dhcp
 post-up ethtool -K eth0 tx off




I am a stumped on this and it is causing some problems for some of the applications that are being tested across the virtual machines. For example, one app on one vm needs to connect to a database, on another vm, but it can't and complains. Do any of you know what might be causing this or any ways to fix this? Thanks in advance.

mike




_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

<Prev in Thread] Current Thread [Next in Thread>