Xen: Booting Additional Domains Under Domain 0
 

Hi there,

Just successfully booted into Dom 0 of my 2.6.13 kernel on opensuse 10.0. my physical memory is 256MB with a 30G hard disk.

Below is my xen entry in menu.1st

loxie:/etc/xen # cat /boot/grub/menu.lst
# Modified by YaST2. Last modification on Mon Jan 23 21:41:25 GMT+1 2006

color white/blue black/light-gray
default 0
timeout 5
gfxmenu (hd0,4)/message

###Don't change this comment - YaST2 identifier: Original name: linux###
title SUSE LINUX 10.0
root (hd0,4)
kernel /vmlinuz root=/dev/hda6 vga=0x314 selinux=0 resume=/dev/hda7 splash=silent showopts
initrd /initrd

###Don't change this comment - YaST2 identifier: Original name: windows###
title Windows
chainloader (hd0,0)+1

###Don't change this comment - YaST2 identifier: Original name: floppy###
title Floppy
chainloader (fd0)+1

###Don't change this comment - YaST2 identifier: Original name: failsafe###
title Failsafe -- SUSE LINUX 10.0
root (hd0,4)
kernel /vmlinuz root=/dev/hda6 vga=normal showopts ide=nodma apm=off acpi=off noresume selinux=0 nosmp noapic maxcpus=0 edd=off 3
initrd /initrd

###########Xen Configuration################
title Xen 3.0 / XenLinux 2.6
root (hd0,4)
kernel /boot/xen-3.0.gz dom0_mem=192M
module /boot/vmlinuz-xen root=/dev/hda6 console=tty0
module /boot/initrd-xen

my disk free space is

loxie:/etc/xen # df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda6 7.3G 6.2G 726M 90% /
tmpfs 118M 12K 118M 1% /dev/shm
/dev/hda5 99M 19M 76M 20% /boot
/dev/hda1 8.8G 8.2G 674M 93% /windows/C
/dev/hda2 10G 9.9G 169M 99% /windows/D
/dev/hda4 1.2G 719M 447M 62% /extra


the xen kernel boots well into Dom 0 but getting additional VM to boot is difficult

my config file for the vm is


loxie:/etc/xen # cat xmexample1
# -*- mode: python; -*-
#============================================================================
# Python configuration setup for 'xm create'.
# This script sets the parameters used when a domain is created using 'xm create'.
# You use a separate script for each domain you want to create, or
# you can set the parameters for the domain on the xm command line.
#============================================================================

#----------------------------------------------------------------------------
# Kernel image file.
kernel = "/boot/vmlinuz-2.6.13-15-xen"

# Optional ramdisk.
ramdisk = "/boot/initrd-2.6.13-15-xen"

# The domain build function. Default is 'linux'.
#builder='linux'

# Initial memory allocation (in megabytes) for the new domain.
memory = 100

# A name for your domain. All domains must have different names.
name = "debloxie"

# Which CPU to start domain on?
#cpu = -1 # leave to Xen to pick

# Number of Virtual CPUS to use, default is 1
#vcpus = 1

#----------------------------------------------------------------------------
# Define network interfaces.

# Number of network interfaces. Default is 1.
#nics=1

# Optionally define mac and/or bridge for the network interfaces.
# Random MACs are assigned if not given.
#vif = [ 'mac=aa:00:00:00:00:11, bridge=xenbr0' ]

#----------------------------------------------------------------------------
# Define the disk devices you want the domain to have access to, and
# what you want them accessible as.
# Each disk entry is of the form phy:UNAME,DEV,MODE
# where UNAME is the device, DEV is the device name the domain will see,
# and MODE is r for read-only, w for read-write.

disk = [ 'phy:/dev/hda6,hda6,r' ]

#----------------------------------------------------------------------------
# Define to which TPM instance the user domain should communicate.
# The vtpm entry is of the form 'instance=INSTANCE,backend=DOM'
# where INSTANCE indicates the instance number of the TPM the VM
# should be talking to and DOM provides the domain where the backend
# is located.
# Note that no two virtual machines should try to connect to the same
# TPM instance. The handling of all TPM instances does require
# some management effort in so far that VM configration files (and thus
# a VM) should be associated with a TPM instance throughout the lifetime
# of the VM / VM configuration file. The instance number must be
# greater or equal to 1.
#vtpm = [ 'instance=1,backend=0' ]

#----------------------------------------------------------------------------
# Set the kernel command line for the new domain.
# You only need to define the IP parameters and hostname if the domain's
# IP config doesn't, e.g. in ifcfg-eth0 or via DHCP.
# You can use 'extra' to set the runlevel and custom environment
# variables used by custom rc scripts (e.g. VMID=, usr= ).

# Set if you want dhcp to allocate the IP address.
#dhcp="dhcp"
# Set netmask.
#netmask=
# Set default gateway.
#gateway=
# Set the hostname.
#hostname= "vm%d" % vmid

# Set root device.
root = "/dev/hda6 ro"

# Root device for nfs.
#root = "/dev/nfs"
# The nfs server.
#nfs_server = '169.254.1.0'
# Root directory on the nfs server.
#nfs_root = '/full/path/to/root/directory'

# Sets runlevel 4.
extra = "3"

#----------------------------------------------------------------------------
# Set according to whether you want the domain restarted when it exits.
# The default is 'onreboot', which restarts the domain when it shuts down
# with exit code reboot.
# Other values are 'always', and 'never'.

#restart = 'onreboot'

#============================================================================

what i noticed is that the memory of 100M doesnt allow the VM to boot its states thus on executing the xm create command

loxie:/etc/xen # xm create -c xmexample1 vmid=-1
using config file xmexample1
error: error 2 (file or directory not found)

but it tries to do a little booting when i reduced the memory to like 16M but stops abruptly complaining of VFS stuffs

Pls can u expantiate in detail what this part of the onfig is all about:

disk = [ 'phy:/dev/hda6,hda6,r' ]

i am getting it all confusing

Thanks