On Wed, 19 Aug 2009 12:15:44 +0000, Andy Smith <andy@???> wrote:
>> Why is this? I thought that, at least on Ubuntu a 'shutdown -r' picks up
>> the latest kernel?!
>
> On a normal machine with grub, a reboot gets you to the point where
> the BIOS runs grub and grub gets kernel, initrd, etc.
>
> On a Xen domU with pygrub, on domain creation pygrub runs in dom0
> (the host server) to read your filesystem, extract your grub config
> file, parse it to find the kernel, initrd etc., extract *those* to
> a temporary directory and then create a domU with those files.
>
> But on a reboot, Xen never actually destroys the virtual machine, it
> just starts it again. That means it will have the same kernel
> (pygrub is never run), same amount of RAM, most probably the same
> size disk devices as well (I have never tested that bit).
Does that apply for domUs virtualised under HVM too? I thought a reboot on
an HVM domU went all the way back to the BIOS.
Tony
