Re: [gentoo-user] installing Gentoo as a xen guest

["Håkon Alstadheim" <hakon@alstadheim.priv.no>]

Den 24. sep. 2015 14:53, skrev Rich Freeman:
> On Thu, Sep 24, 2015 at 6:05 AM, hw <hw@gc-24.de> wrote:
>> Hi,
>>
>> I'm installing Gentoo as a xen PV guest.  Do I need to install a bootloader
>> like grub, or should I rather just specify the kernel to boot in the
>> definition file of the guest?  If I do the latter, what about the kernel
>> command line?
>>
>> Is there anything I should consider?  The host is also running Gentoo.
>>
> You can do either.  I suspect it would be easier to just use grub.  I
> don't know if xen provides a way to provide a command-line, if not you
> could build a default command-line into your kernel.
>
Depending on your hardware you will want to use hvm or pvm for
efficiency. (VT-x means hvm is more efficient). If running hvm on
quemu-xen-traditional, you HAVE to use a bootloader inside the VM, or
some kind of netboot/pvgrub thing. If running upstream quemu for a hvm,
you can choose. I find it less of a hassle to use bootloader inside the
VM. If running pv, I BELIEVE you have to specify kernel and boot options
outside the VM-image, possibly through pvgrub. Pvgrub is supposed to be
able to fish out kernel and initrd from the VM disk. I never bothered to
get that working. Here is an example excerpt from a PVM I use (for a
debian vm):
--print.pvm---
builder = "generic"
kernel = "/etc/xen/wheezy/vmlinuz-3.16.0-0.bpo.4-amd64"
ramdisk = "/etc/xen/wheezy/initrd.img-3.16.0-0.bpo.4-amd64"
extra = "root=/dev/xvda console=hvc0 tmem"
--
For explanation check "man xl.cfg". When you specify
kernel&ramdisk&parameters in the vm config, you do NOT need a /boot/
directory on your vm.  Obviously when you build a kernel inside the vm,
it will end up in /boot, so you have to provide a way for the
dom0/hypervisor to load your kernel, either (when using full
virtualization) a regular boot-loader inside the vm, or (for a PV guest)
through some other means to let the dom0/hypervisor load your image.