network problems when booting linux vm's

[peejee]

Hello,

In our school we use proxmox as virtualisation platform for our servers.
On each proxmox we have a windows server, an ubuntu ltsp server and a zentyal server (distribution based on ubuntu, used as domain controller, dhcp-server, ...)

When booting windows there are never problems, that works fluently.

But when booting a linux server, most of the time the network doesn't get enabled. I never can reach the servers. Sometimes (after trying several times, always different) the machine is booting ok and everything is working as it should.

It's very strange and we don't know what we're doing wrong. We have 3 machines with proxmox and they all have the same problem.

Underneath a picture of the configuration of the network on proxmox on one of the vm's.



(all vm's use the same 2 physical network cards)

 

[udo]

Hello,

In our school we use proxmox as virtualisation platform for our servers.
On each proxmox we have a windows server, an ubuntu ltsp server and a zentyal server (distribution based on ubuntu, used as domain controller, dhcp-server, ...)

When booting windows there are never problems, that works fluently.

But when booting a linux server, most of the time the network doesn't get enabled. I never can reach the servers. Sometimes (after trying several times, always different) the machine is booting ok and everything is working as it should.

It's very strange and we don't know what we're doing wrong. We have 3 machines with proxmox and they all have the same problem.

Underneath a picture of the configuration of the network on proxmox on one of the vm's.

View attachment 1383

(all vm's use the same 2 physical network cards)

Hi,
normaly linux-guest works much better than windows

Can you post your pveversion and the config of the VMs and network? Have you tried to use virtio instead of e1000? For linux guests you can simply edit the config and stop/start and all should work.

pveversion -v
cat /etc/pve/qemu-server/VMID.conf
cat /etc/network/interfaces

Udo

 

[peejee]

Hello,

I never tried virtio. (Because I only know e1000 to create a gigabit network to reach my servers). I will try that the first time when nobody is in school. What is in fact the difference?

Our pve-version:

pve-manager: 2.1-1 (pve-manager/2.1/f9b0f63a)
running kernel: 2.6.32-11-pve
proxmox-ve-2.6.32: 2.0-66
pve-kernel-2.6.32-11-pve: 2.6.32-66
lvm2: 2.02.95-1pve2
clvm: 2.02.95-1pve2
corosync-pve: 1.4.3-1
openais-pve: 1.1.4-2
libqb: 0.10.1-2
redhat-cluster-pve: 3.1.8-3
resource-agents-pve: 3.9.2-3
fence-agents-pve: 3.1.7-2
pve-cluster: 1.0-26
qemu-server: 2.0-39
pve-firmware: 1.0-15
libpve-common-perl: 1.0-27
libpve-access-control: 1.0-21
libpve-storage-perl: 2.0-18
vncterm: 1.0-2
vzctl: 3.0.30-2pve5
vzprocps: 2.0.11-2
vzquota: 3.0.12-3
pve-qemu-kvm: 1.0-9
ksm-control-daemon: 1.1-1

The zentyal qemu config file:

bootdisk: ide0
cores: 4
ide0: local:100/vm-100-disk-1.qcow2
ide2: local:iso/zentyal-2.2-2-amd64.iso,media=cdrom
memory: 24576
name: zentyal-sap-01
net0: e1000=D2:98:1D:EF:91:18,bridge=vmbr0
net1: e1000=7E:856:05:35:73,bridge=vmbr1
net2: e1000=82:BB:5F:55:BD:2E,bridge=vmbr2
ostype: l26
sockets: 4
startup: order=1

the interfaces configuration

auto lo
iface lo inet loopback


iface eth0 inet manual


iface eth1 inet manual


iface eth2 inet manual


auto vmbr0
iface vmbr0 inet static
address 172.16.108.2
netmask 255.255.255.0
gateway 172.16.108.254
bridge_ports eth0
bridge_stp off
bridge_fd 0


auto vmbr1
iface vmbr1 inet static
address 10.0.0.2
netmask 255.255.0.0
bridge_ports eth1
bridge_stp off
bridge_fd 0


auto vmbr2
iface vmbr2 inet static
address 192.168.0.254
netmask 255.255.255.0
bridge_ports eth2
bridge_stp off
bridge_fd 0

 

[udo]

Hello,

I never tried virtio. (Because I only know e1000 to create a gigabit network to reach my servers). I will try that the first time when nobody is in school. What is in fact the difference?

Hi,
the difference is better speed/cpu-usage ratio (but with smp and virtio you should have an recent kernel 3.x).

Our pve-version:

of course is the recommendation to upgrade to the latest stable version (2.3).

The zentyal qemu config file:

Looks ok for me

the interfaces configuration

any info about network in the logs?
What do you see on the host, if you start an VM (which are not able to connenct to the network)?
Look with "tcpdump -i vmbr1 -h ip.of.gue.st" (or vmbr2)
Look also "ifconfig tap100i0" and tap100i1/2

Udo

 

[vga]

Had the same problem...
I made simple workaround script:
/etc/init.d/networkfix

#!/bin/sh
#
# chkconfig: - 11 90
# description: Restart network if gateway (192.168.0.1) unreachable.

PATH=/bin:/usr/bin:/sbin:/usr/sbin:/usr/local/bin:/usr/local/sbin

n=1
while [ $n -le 10 ]
do
    if ! ping -c 3 192.168.0.1 > /dev/null
    then
        /etc/init.d/network restart
        n=`expr $n + 1`
    else
        echo "Network was started after $n attemps."
        exit
    fi
done

echo "Network was not started."

Then I added this script to start at 3-5 runlevels.
It must start immediately after network. Before other services.

 

[peejee]

Thanks for the answers.
I will try a few things mentioned above but at first it must be weekend or something so I can try when nobody is in the school

Then I will post what happens.

 

[peejee]

Yesterday evening I could shut down all servers and I have changed all the "e1000" network cards to "virtio" after upgrading proxmox to the newest version.
I restarted all the virtual machines 3 times without any problem. It seems all problems are solved which is great!

thanks a lot!