Xen users - Sep 2007 - PV guest kernel location

Still new at this and was wondering if someone could give me some 
pointers.  I have Xen 3.0.4 running great with 5 PV guests.  I just 
followed setup instructions from a few wiki pages.  But the one thing I 
noticed, is that the guest kernel is on the host.  Below is the cfg file 
for my mail server guest.

#  -*- mode: python; -*-
kernel = "/boot/vmlinuz-2.6.16.33-xen"
ramdisk = "/boot/initrd.img-2.6.16.33-xen"
memory = 256
name = "mail"
vif = [''bridge=xenbr0'']
disk = 
[''file:/vserver/mail/guest_base2G.img,hda1,w'',''file:/vserver/mail/guest_swap256M.img,hda2,w'',''phy:data/mail,hda3,w'']
ip = "192.168.10.43"
netmask = "255.255.255.0"
gateway = "192.168.10.1"
hostname = "mail"
root = "/dev/hda1 ro"
extra = "4"

  I see post talking about 32bit guests on 64bit hosts.  How do you do 
that?  My main question is, how can I create a PV guest that is self 
contained for files?  I want to pick up my guest and move it to another 
system without worrying if the same kernel is available on the new 
host.  I can''t seem to find a wiki that gives these types of
instructions.

  Can the kernel be copied into the guest and the guest boot from those 
file?  How would my above cfg change?

Thanks in advance for any help provided.
Greg


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Well, since nobody answered, I''ll do it myself.  With much pain and 
suffering of trial and error, I figure it out.  Turns out, it is the 
very well undocumented feature called pygrub.  The following is how I 
converted my PV guest mentioned below into having its own kernel and 
pygrub boot.

  My host system is running Xen 3.0.4 x86_64 on Ubuntu 6.06.  Soon to be 
3.1.0.  My guests are all x86_64 Ubuntu 6.06 as well.

**** FROM THE PV GUEST ****
1. First, I downloaded the tarballs for xen 3.0.4 and 3.1.0 for x86_64 
(since my guests were x86_64).
xen-3.0.4_1-install-x86_64.tgz
xen-3.1.0-install-x86_64.tgz

2. Remove/rename the old /lib/modules/2.6.16.33-xen, which was my kernel 
from 3.0.4 install.

3. Run the install.sh for each.

4. Create a file called /boot/grub/menu.lst with the following.

default         2
timeout         5

title           Ubuntu, memtest86+
root            (hd0,0)
kernel          /boot/memtest86+.bin
boot

title           Xen 3.0.4 vmlinuz-2.6.16.33-xen
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.16.33-xen root=/dev/hda1 ro splash
savedefault
boot

title           Xen 3.1.0 vmlinux-syms-2.6.18-xen
root            (hd0,0)
kernel          /boot/vmlinux-syms-2.6.18-xen root=/dev/hda1 ro splash
savedefault
boot

5. shutdown -h now

**** FROM THE HOST ***
6. Change the cfg file below to look like this.  Remove all kernel stuff 
and add bootloader.
#  -*- mode: python; -*-
memory = 256
name = "mail"
vif = [''bridge=xenbr0'']
disk = 
[''file:/vserver/mail/guest_base2G.img,hda1,w'',''file:/vserver/mail/guest_swap256M.img,hda2,w'',''phy:data/mail,hda3,w'']
bootloader = ''/usr/bin/pygrub''

7. Start the new domU.
  xm create -c xmguest-mail

*******

  That''s it.  It''s nice that the domU has it''s own
copy of the kernel
now and doesn''t boot the kernel hosted on the host filesystem.  Also,
it
will make it easier if I have to move this domU to another system.

  I did run into one strange problem.  When I first ran the ''xm
create''
for each domU I converted, it failed saying ''nothing
returned''.  I found
that strange, but when I tried the 2nd time for each, it worked.  I hope 
it has nothing to do with running Xen 3.1.0 guests from pygrub on 3.0.4 
host.

  Hope people find this useful.  I wish there was more info on this 
topic from people that know how this works.  Also more info on the 
difference between file backed file: compared to tap:aio:.

Greg


Gregory Gee wrote:
>
>  Still new at this and was wondering if someone could give me some 
> pointers.  I have Xen 3.0.4 running great with 5 PV guests.  I just 
> followed setup instructions from a few wiki pages.  But the one thing 
> I noticed, is that the guest kernel is on the host.  Below is the cfg 
> file for my mail server guest.
>
> #  -*- mode: python; -*-
> kernel = "/boot/vmlinuz-2.6.16.33-xen"
> ramdisk = "/boot/initrd.img-2.6.16.33-xen"
> memory = 256
> name = "mail"
> vif = [''bridge=xenbr0'']
> disk = 
>
[''file:/vserver/mail/guest_base2G.img,hda1,w'',''file:/vserver/mail/guest_swap256M.img,hda2,w'',''phy:data/mail,hda3,w'']
>
> ip = "192.168.10.43"
> netmask = "255.255.255.0"
> gateway = "192.168.10.1"
> hostname = "mail"
> root = "/dev/hda1 ro"
> extra = "4"
>
>  I see post talking about 32bit guests on 64bit hosts.  How do you do 
> that?  My main question is, how can I create a PV guest that is self 
> contained for files?  I want to pick up my guest and move it to 
> another system without worrying if the same kernel is available on the 
> new host.  I can''t seem to find a wiki that gives these types of 
> instructions.
>
>  Can the kernel be copied into the guest and the guest boot from those 
> file?  How would my above cfg change?
>
> Thanks in advance for any help provided.
> Greg
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users

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