XEN: "x0" re-spawning too fast message in DomU console

This document (7000048) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 10 Service Pack 2
SUSE Linux Enterprise Server 10 Service Pack 1

Situation

SLES 10 SP1 and other some other Linux distributions may have the following errors.

In /var/log/messages:

init: Id "x0" respawning too fast: disabled for 5 minutes

In /var/log/messages:

Apr 13 17:02:43 bhoward5 agetty[8511]: /dev/xvc0: No such file or directory
Apr 13 17:02:53 bhoward5 agetty[8927]: /dev/xvc0: No such file or directory
Apr 13 17:03:03 bhoward5 agetty[8929]: /dev/xvc0: No such file or directory

On the console:

init: Id "x0" respawning too fast: disabled for 5 minutes

Resolution

Between SLES 10 and SLES 10 SP1, the version of Xen changed. In 3.04. A new console device, /dev/xvc0 was introduced to handle the console. This error is typically seen on DomU's which support "xvc0" but have been configured with legacy options.

match compatibility
To see if this method will work on your DomU, check /etc/inittab. The file should have a similar line. If the line does not exist and it is SLES 10 SP1 or later, you may add it. For other Linux distributions, please check with the vendor.

x0:12345:respawn:/sbin/agetty -L 9600 xvc0 xterm

method 1: simple configuration file
This method is recommended for DomU's that are unmanaged.

Shutdown the DomU
Go to /etc/xen/vm and locate the configuration file
Backup the configruation file
Open the file for editing
Locate the "extra" line
Replace the line with
extra="console=xvc0"
Save and close the file
Test the configuration

Example Configuration:

name="bh7-oes"
memory=512
uuid="d2774884-ebe8-dc4d-f07c-9639f413d4c9"
vcpus=2
on_poweroff="destroy"
on_reboot="restart"
on_crash="destroy"
localtime=0
builder="linux"
bootloader="/usr/lib/xen/boot/domUloader.py"
bootargs="--entry=xvda1:/boot/vmlinuz-xenpae,/boot/initrd-xenpae"
extra="console=xvc0"
disk=[ 'file:/var/lib/xen/images/bh7-oes/disk0,xvda,w', ]
vif=[ 'mac=00:16:3e:89:c2:f2', ]
vfb=['type=vnc,vncunused=1']

method 2: method 1 plus importing
This method is for managed DomU's that have not been altered by management tools like "virt-manager", YaST or "virt-manager"

Follow method 1
Import the change
xm new -f NAME_OF_DOMU

method 3: for modified managed domains
This method is not recommended unless you have modified a managed domain, as it involves exporting the configration from the Xen store and then editing the Python manually.

Export the configuration
xm list -l SLES10 > SLES10.py
Backup the exported configuration file
Open the file for editing
Locate the following (or similiar).
(linux
(kernel )
(args 'TERM=XTERM xencons=tty')
(device_model /usr/lib/xen/bin/qemu-dm)
Change it to
(linux
(kernel )
(args 'console=xvc0')
(device_model /usr/lib/xen/bin/qemu-dm)
Save and close the file
Import the changes
xm new -F SLES10

Disclaimer

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