Installing in a PV (para-virtualized) machine

To install a Xen Guest Os from the first time, you need to:

• Create the Filesystems for it on the Xen Host:

  vgdisplay
  lvcreate -L 12G -n ui64_root vg_root
  lvcreate -L 4G -n ui64_swap vg_root
  lvdisplay

• Create the Xen config file for the machine in /etc/xen/ui64 with this content:

  name = "ui64"
  
  vcpus = 2
  memory = 2048
  disk = ['phy:/dev/vg_root/ui64_root,xvda,w',
          'phy:/dev/vg_root/ui64_swap,xvdb,w']
  vif = ['mac=00:16:3E:64:00:64,bridge=xenbr0']
  
  kernel = '/root/xenkernel/sl54_64/vmlinuz'
  ramdisk = '/root/xenkernel/sl54_64/initrd.img'
  on_reboot = 'destroy'
  on_crash = 'destroy'

• Make sure there exists both vmlinuz and initrd.img from above in the Xen Host. They come from the /images/xen directory on the SL54 first CD, or in the repo.
• Start the virtual machine and open the vnc console: xm create -c ui64
• The xen console will come up, just make a normal installation as desired. Network is left to be configured with dhcp. You may also want to use a local repository or the one at ftp://mirror.switch.ch/mirror/scientificlinux/54/x86_64/
• After installation the machine will halt. To go on we need to replace the old /etc/xen/ui64 with this new one:

  name = "ui64"
  
  vcpus = 2
  memory = 2048
  disk = ['phy:/dev/vg_root/ui64_root,xvda,w',
          'phy:/dev/vg_root/ui64_swap,xvdb,w']
  vif = ['mac=00:16:3E:64:00:64,bridge=xenbr0']
  
  bootloader = "/usr/bin/pygrub"

• Then you can boot up again with xm create -c ui64

Installing in a HVM with CD and then converting it to PV.

OBSOLETE, DOESN'T WORK

There's some info here:

http://markmail.org/message/ib5bctd3amqqzl5u#query:convert%20hvm%20xen%20to%20paravirtual%20initrd+page:1+mid:pg3g44k5cdmuyqes+state:results
http://old.nabble.com/Converting-full-virtualized-Linux-domUs-to-use-paravirtualized-drivers-td18942359.html

To install a Xen Guest Os from the first time, you need to:

• Create the Filesystems for it on the Xen Host:

  vgdisplay
  lvcreate -L 12G -n ui64_root vg_root
  lvcreate -L 4G -n ui64_swap vg_root
  lvdisplay

• Create the Xen config file for the machine in /etc/xen/ui64 with this content:

  name = "ui64"
  
  vcpus = 2
  memory = 2048
  disk = ['phy:/dev/vg_root/ui64_root,hda,w',
          'file:/root/SL.54.110309.DVD.x86_64.disc1.iso,hdc:cdrom,r',
          'phy:/dev/vg_root/ui64_swap,hdb,w']
  vif = ['mac=00:16:3E:64:00:64,bridge=xenbr0']
  
  builder = "hvm"
  kernel = "/usr/lib/xen/boot/hvmloader"
  device_model = "/usr/lib64/xen/bin/qemu-dm"
  pae = 1
  boot = "cd"
  vnc = 1
  vncviewer = 1
  vncdisplay = 7

• Start the virtual machine and open the vnc console:

  xm create ui64
  vncviewer localhost:7

• Finish the installation (the least software installed the better), confirm reboot. Then shut down the machine with xm destroy ui64
• Backup the basic installation if wanted. From the Xen Host perform

  dd if=/dev/vg_root/ui64_root of=/root/ui64_root.img

• Upon restart remove all unnecesary services from bootup, and edit the /etc/modprobe.conf file to be like this. After a kernel reinstallation (or running mkinitrd manually) the initrd image will be able to boot from paravirtualized devices:

  alias eth0 xennet
  alias scsi_hostadapter xenblk 

• Finally install the xen kernel, which should be on the cdrom (mount it first) and uninstall the non-xen one.

  mount /dev/hdc /mnt
  rpm -i /mnt/SL/kernel-xen-2.6.18-164.2.1.el5.x86_64.rpm
  rpm -i /mnt/SL/kernel-xen-devel-2.6.18-164.2.1.el5.x86_64.rpm
  rpm -e kernel-devel-2.6.18-164.2.1.el5.x86_64 kernel-2.6.18-164.2.1.el5.x86_64
  cat /boot/grub/menu.lst

• Then check the xen kernel is the default to be loaded on boot, and halt the VM.
• Before starting it again, replace the /etc/xen/ui64 xen config file to match this content (to be para-virtualized):

  name = "ui64"
  
  vcpus = 2
  memory = 2048
  disk = ['phy:/dev/vg_root/ui64_root,hda,w',
          'phy:/dev/vg_root/ui64_swap,hdb,w']
  vif = ['mac=00:16:3E:64:00:64,bridge=xenbr0']
  
  bootloader = "/usr/bin/pygrub"

-- PabloFernandez - 2010-02-15</verbatim>