Re: Ubuntu 20.04 domu problem

[Andy Smith <andy@xxxxxxxxxxxxxx>]

Hello,

On Tue, Nov 10, 2020 at 01:57:14PM -0800, Bill MacAllister wrote:
> I am working on moving our Xen servers to Ubuntu 20.04 and am having
> problems creating domu's using xen-tools.

[…]

> At this point I started just hacking.  I changed to using pvgrub by
> commenting out the 'bootloader' parameter in the domu configuration file and
> added the line 'which resulted in booting the container to the "grub>"
> prompt.  But with the domu's /boot empty this of course did not lead
> anywhere.  I then just hacked on
> /usr/share/xen-tools/focal.d/82-install-grub-legacy and changed the install
> line to 'grub2'.  With that the domu boot directory was not empty, but the
> boot still stopped at the 'grub>' prompt.

I haven't looked at pygrub in quite a few years, having moved to
pvgrub, but please note that Ubuntu 20.04 uses LZ4-compressed
kernels which pvgrub doesn't currently support.

If wanting to do pvgrub with Ubuntu 20.04 you'll need to decompress
the kernels with something like this:

    https://github.com/bitfolk/decompress-lz4-kernels

Or switch to PVH, which has no such problems.

Cheers,
Andy