[Bug 2063821] [NEW] Ubuntu 22.04 server installer doesn't boot on Xen server as domU in PVH mode

[Neil du Preez]

Public bug reported:

The Xen server I am working on has Debian 12 as dom0. As mentioned in
the summary I am trying to install Ubuntu 22.04 server as a domU in PVH
mode.

I tested using ubuntu-22.04.4-live-server-amd64.iso.

This is the domU configuration I used. It attempts to use PVHGRUB:

  name = "ubuntu-2204"
  memory = 1024
  maxmem = 1024
  vcpus = 1
  vif = [ 'bridge=xenbr0' ]
  disk = [ '/root/ubuntu-22.04.4-live-server-amd64.iso,raw,xvdg,r,cdrom', 
'/dev/myvg/ubuntu-2204-root,raw,xvda,rw', 
'/dev/myvg/ubuntu-2204-swap,raw,xvdb,rw' ]
  type = "pvh"
  kernel = "/usr/lib/grub-xen/grub-i386-xen_pvh.bin"

I can see the grub menu, and I edit the first entry (Try or install
Ubuntu) by appending "console=hvc0 nosplash" to the end of the kernel
commandline.

I can then see console output scrolling past, until this point:

  Begin: Running /scripts/init-premount ... done.
  Begin: Mounting root file system ... Begin: Running /scripts/nfs-top ... done.
  Begin: Running /scripts/nfs-premount ... done.
  Begin: Running /scripts/casper-premount ... done.
  done.
  Unable to find a medium containing a live file system
  Attempt interactive netboot from a URL?
  yes no (default yes): no


  BusyBox v1.30.1 (Ubuntu 1:1.30.1-7ubuntu3) built-in shell (ash)
  Enter 'help' for a list of built-in commands.

  (initramfs) Unable to find a medium containing a live file system

I then destroyed the domU and tried the following domU config in PV mode
instead. The kernel and ramdisk were extracted from the ISO:

  name = "ubuntu-2204"
  memory = 1024
  maxmem = 1024
  vcpus = 1
  vif = [ 'bridge=xenbr0' ]
  disk = [ '/root/ubuntu-22.04.4-live-server-amd64.iso,raw,xvdg,r,cdrom', 
'/dev/myvg/ubuntu-2204-root,raw,xvda,rw', 
'/dev/myvg/ubuntu-2204-swap,raw,xvdb,rw' ]
  type = "pv"
  kernel = "/root/ubuntu-2204-vmlinuz"
  ramdisk = "/root/ubuntu-2204-initrd"
  extra = "console=hvc0 nosplash"

The above config allows me to install the OS successfully over the
serial console using the standard server installer. After installation
is complete, I can boot the newly installed VM with PVHGRUB in PVH mode
using this config:

  name = "ubuntu-2204"
  memory = 1024
  maxmem = 1024
  vcpus = 1
  vif = [ 'bridge=xenbr0' ]
  disk = [ '/dev/myvg/ubuntu-2204-root,raw,xvda,rw', 
'/dev/myvg/ubuntu-2204-swap,raw,xvdb,rw' ]
  type = "pvh"
  kernel = "/usr/lib/grub-xen/grub-i386-xen_pvh.bin"

I expected to be able to install the Ubuntu 22.04 domU in PVH mode with
PVHGRUB.

Instead I had to install the Ubuntu 22.04 domU in PV mode as described
above. It was only after successful installation in PV mode, that I
could boot the installed domU in PVH mode.

** Affects: xen (Ubuntu)
 Importance: Undecided
 Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2063821

Title:
  Ubuntu 22.04 server installer doesn't boot on Xen server as domU in
  PVH mode

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/xen/+bug/2063821/+subscriptions


-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

[Bug 2063821] Re: Ubuntu 22.04 server installer doesn't boot on Xen server as domU in PVH mode

[Neil du Preez]

Thank you for your reply.

My main goal was to raise awareness since it wasn't clear to me whether
anyone was aware of this issue. As I mentioned previously, it would be
great to be able to install in PVH mode since it is "the best" mode
currently available as I understand it based on this page:

https://wiki.xenproject.org/wiki/Understanding_the_Virtualization_Spectrum

I have (subsequently to submitting this report) encountered similar
behaviour with a Debian 12 installer, so it is not Ubuntu-specific.

Unfortunately I don't have time to dig much deeper into this, and the
workaround I mentioned works well. I have / will mention it again on
Debian channels as well.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2063821

Title:
  Ubuntu 22.04 server installer doesn't boot on Xen server as domU in
  PVH mode

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/xen/+bug/2063821/+subscriptions


-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs