XEN: Passing kernel parameters to para-virtual DomU's.

This document (7001929) is provided subject to the disclaimer at the end of this document.

Environment

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

Situation

A kernel paremeter needs to be passed to a para-virtual Xen DomU.

Resolution

The passing of kernel parameters is handled by the extra= directive in the Xen configuration file.

unamanaged domain: single boot passing of parameters
This method is used for DomU's that are not started, stopped OR have had their hardware altered through "xm" commands, Virt-Manager or YaST. This method can also be used for managed DomU's that have not had any hardware changes since the installation of the DomU.

Simply start the DomU with the "extra=" syntax. For example:

xm create DOMU extra=" init 2"

unmanaged domain: permanent passing of parameters
This method is used for DomU's that are not started, stopped OR have had their hardware altered through"xm" commands, Virt-Manager or YaST. This method can also be used for managed DomU's that have not had any hardware changes since the installation of the DomU.

Locate the configuration file.
Locate the "extra=" directive
Add the parameter within the "'s
Save the file
Start the DomU normally

Importing new managed DomU configuration file, replace "domu" with the name of the file. This step only applies for managed DomU's.

xm new -f domu

managed domain: single boot passing of parameters
This method is used for DomU's that are started, stopped AND/OR have had their hardware altered through "xm" commands, Virt-Manager or YaST.

Export the configuration from the xenstore, replace "DOMU" with the name of the DomU
xm list -l DOMU > domu.py
Start the DomU by adding extra="", for example
xm create -F domu.py extra=" init 1"

managed domain: permanent passing of parameters
This method is used for DomU's that are started, stopped AND/OR have had their hardware altered through "xm" commands, Virt-Manager or YaST.

Export the configuration from the XenStore
xm list -l DOMU > domu.py
Open the file for editing
File the (arg ' ') parameter. It may look similiar to this:
    (image
        (linux
            (kernel )
            (args ' ')
            (device_model /usr/lib/xen/bin/qemu-dm)
            (notes
Put your parameter within the ' '. For example:
    (image
        (linux
            (kernel )
            (args ' init 1')
            (device_model /usr/lib/xen/bin/qemu-dm)
            (notes
Save the file
Test it to make sure that the DomU will start
xm create -F domu.py
If you are satified that the DomU will start correctly, shutdown the DomU
Import the configuration file
xm new -F domu.py
Start the DomU normally

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