[Fedora-xen] pygrub failed

[Stephen C. Tweedie]

Hi,

On Sun, 2006-04-02 at 22:09 -0400, Winston Chang wrote:
> The installer will create the disk image and partition it.  If you do  
> not successfully run to the installer, "xm create -c xxxx" will not  
> work.  The script gives bad instructions when an error occurs.
> 
> The Xen hypervisor takes 32MB of RAM (I think), so you have to make  
> sure that your dom0 gets less than 224MB.  I gave mine 192MB, with  
> the following in grub.conf:
>    kernel /xen.gz-2.6.15-1.2054_FC5 dom0_mem=196608

Actually, you should be able to do that manually with 

        xm mem-set 0 192
        
to balloon the dom0 down to 192MB.  It won't balloon automatically below
256MB, but can do so if explicitly told to.

> In my opinion, the xenguest-install.py method isn't very good at this  
> point.
> - The installer gives poor feedback when something goes wrong, like  
> when memory is too low.

Agreed, it could well be improved.

> - pygrub crashes if your terminal emulation is a little weird
> - It creates a whole disk image instead of importing partitions.   
> This makes it difficult to access domU filesystems from dom0, but  
> this is often necessary for management.

That's just part of the goal of making the domU environment as similar
as possible to the dom0.  Having a single disk image passed in means you
can keep boot info, root fs and swap all in the same place in the host
OS.

> - It doesn't provide an option for creating images on LVM volumes.

If you already have an LVM volume, you can simply specify that and it
just works (most of my test xen installs are to LVM.)

> Or you could use a kernel from xensource that has the xennet driver  
> compiled into the kernel.  I don't know why the developers decided to  
> take the driver out of the kernel.  

The default networking with Xen uses netfront/back and bridging, so
that's what we compile in.  Is there really a strong need for xennet
too?

> Pretty much everyone would want  
> networking on their domU machines, and adding it in this way is just  
> more complicated.

With FC-5 default networking, things just work (though it definitely can
interact badly with more complex networking setups); what exactly is
complicated and needs fixed?

--Stephen