gpg: Signature made Thu Nov 12 09:39:22 2020 UTC
gpg: using DSA key 2099B64CBF15490B
gpg: Good signature from "Andy Smith <andy@strugglers.net>" [unknown]
gpg: aka "Andrew James Smith <andy@strugglers.net>" [unknown]
gpg: aka "Andy Smith (UKUUG) <andy.smith@ukuug.org>" [unknown]
gpg: aka "Andy Smith (BitFolk Ltd.) <andy@bitfolk.com>" [unknown]
gpg: aka "Andy Smith (Linux User Groups UK) <andy@lug.org.uk>" [unknown]
gpg: aka "Andy Smith (Cernio Technology Cooperative) <andy.smith@cernio.com>" [unknown]
Hi Chris,
On Thu, Nov 12, 2020 at 08:41:17AM +0000, Chris Smith via users wrote:
> Are you saying that it is not possible to install Ubuntu 20.04
> currently without a kernel hack?
TL;DR: Maybe you want to wait a week or two and then do your
upgrade and switch to PVH mode, which doesn't need this kernel
install hook.
To expand upon what Roger has written - and I would have posted the
same link that Roger did - the issue is just that Ubuntu now use
LZ4-compressed kernels, which pvgrub doesn't yet support, so they
can't be booted in Xen PV mode.
There's a script called extract-linux that lives in the upstream
kernel source. It extracts an uncompressed kernel out of a
compressed image. So, I wrote a script that uses that as a kernel
package install hook. When a new kernel is installed it's
automatically called to get an uncompressed kernel image, which
pvgrub is fine with.
> the Bitfolk site lists 20.04 as an available option.
If a new customer signs up and asks for Ubuntu 20.04 then they get
the kernel decompression hook provided.
If an existing customer uses our Xen Shell to install 20.04 from
scratch then the post-install script that is called automatically
puts the above script in place before first boot.
The result is that ordering or installing 20.04 doesn't require any
extra steps, so that's why it's marked as available.
It's only where someone upgrades in place from 18.04 to 20.04 that
the above hook needs to be manually put in place.
I don't know the best way to inform people about issues with various
Linux distributions. For those using the Xen Shell to install or
upgrade we've tried to collect any useful information here:
https://tools.bitfolk.com/wiki/Self-install
An additional wrinkle now for Ubuntu is that in PVH mode the LZ4
kernels work fine, but the uncompressed ones don't! So if someone is
running 20.04 now or upgrades to it now, and later wants to switch
to PVH mode, they will have to make sure to remove/disable that hook
and regenerate a compressed kernel.
If all of this is confusing, and you can wait a week or two, maybe
it is best to do so. We will have PVH mode available by then, and
then no such kernel hook script is necessary.
Cheers,
Andy
--
https://bitfolk.com/ -- No-nonsense VPS hosting
