33.5. Modifying /etc/grub.conf
This section describes how to safely and correctly change your
/etc/grub.conf file to use the virtualization kernel. You must use the xen kernel to use the Xen hypervisor. Copy your existing xen kernel entry make sure you copy all of the important lines or your system will panic upon boot (initrd will have a length of '0'). If you require xen hypervisor specific values you must append them to the xen line of your grub entry.
The output below is an example of a
grub.conf entry from a system running the kernel-xen package. The grub.conf on your system may vary. The important part in the example below is the section from the title line to the next new line.
#boot=/dev/sda default=0 timeout=15 #splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1 terminal --timeout=10 serial console title Red Hat Enterprise Linux Server (2.6.17-1.2519.4.21.el5xen) root (hd0,0) kernel /xen.gz-2.6.17-1.2519.4.21.el5 com1=115200,8n1 module /vmlinuz-2.6.17-1.2519.4.21.el5xen ro root=/dev/VolGroup00/LogVol00 module /initrd-2.6.17-1.2519.4.21.el5xen.img
Note
Your
grub.conf could look very different if it has been manually edited before or copied from an example. Read Chapter 29, Configuring the Xen kernel boot parameters for more information on using virtualization and grub.
To set the amount of memory assigned to your host system at boot time to 256MB you need to append
dom0_mem=256M to the xen line in your grub.conf. A modified version of the grub configuration file in the previous example:
#boot=/dev/sda default=0 timeout=15 #splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1 terminal --timeout=10 serial console title Red Hat Enterprise Linux Server (2.6.17-1.2519.4.21.el5xen) root (hd0,0) kernel /xen.gz-2.6.17-1.2519.4.21.el5 com1=115200,8n1 dom0_mem=256MB module /vmlinuz-2.6.17-1.2519.4.21.el5xen ro root=/dev/VolGroup00/LogVol00 module /initrd-2.6.17-1.2519.4.21.el5xen.img
