Installing a domU without virt-install

[Andy Burns]

[Re-sent from my list subscribed email address, sorry]

I've got a Fedora 17 dom0, running under Xen 4.2 (thanks to the Pasi's
archive of Michael's test SRPM at
http://pasik.reaktio.net/fedora/xen/xen-4.2.0-0.1.fc17.src.rpm)

Since there's no libvirt support in that build, I had to uninstall the
existing virt-* tools too, therefore no helpers to create a new domU.
However, a link on LWN reminded me of http://boot.fedoraproject.org/
and I wondered if I could use that to get a new domU installed.

I downloaded the boot CD image (only 1MB)

# wget http://dl.fedoraproject.org/pub/alt/bfo/bfo.iso

Created a new logical volume to hold the domU disk on my vg0 volume group

# lvcreate --size=8G --name=mytest vg0

Zeroed the boot sector (especially as I had to have a few attempts to
get it right)

# dd if=/dev/zero of=/dev/mapper/vg0-mytest count=1

Created a config file for the domU

===========
memory = 1024
name = 'mytest'
vif = [ bridge=virbr0' ]
disk = [ 'phy:/dev/mapper/vg0-mytest,
xvda,w', 'file:/root/bfo.iso,hdc:cdrom,r' ]
boot = 'd'
builder = 'hvm'
vcpus = 1
on_reboot = 'restart'
on_crash = 'restart'
vnc = 1
vnclisten = '192.168.1.125'
vncdisplay = 0
stdvga= 1
usb = 1
usbdevice = 'tablet'
===========

Since I'm SSH'ed into the dom0 and want to use VNC from a laptop, I
needed the vnc session to listen on the dom0's IP address not just
localhost, alternatively I could have tunnelled inside the SSH
session, so adjust IP address to suit.

Start the domU

# xl create mytest.cfg

Started VNC viewer to watch bfo booting up, getting IP address via
DHCP, fetching kernel/initramfs/squashfs from the internet, after a
few minutes Anaconda boots into graphical mode and you can perform the
install.

After installation completed, I edited the .cfg file to change the
domU from a HVM to a PV, give it a persistent MAC address, steal some
memory from it and remove the CD drive

memory = 512
name = 'mytest'
vif = [ 'mac=00:16:3e:74:56:59, bridge=virbr0' ]
disk = [ 'phy:/dev/mapper/vg0-mytest,xvda,w' ]
bootloader = 'pygrub'
vcpus = 1
on_reboot = 'restart'
on_crash = 'restart'

re-start the domU with that configuration

# xl create mytest.cfg -c

and the job is done, very neat thanks to all the useful stuff out there.

[M A Young]

On Thu, 1 Nov 2012, Andy Burns wrote:
> [Re-sent from my list subscribed email address, sorry]
>
> I've got a Fedora 17 dom0, running under Xen 4.2 (thanks to the Pasi's
> archive of Michael's test SRPM at
> http://pasik.reaktio.net/fedora/xen/xen-4.2.0-0.1.fc17.src.rpm)

Note there are now official xen-4.2.0 packages for F18 and F19. They 
should rebuild on F17, though offical F17 builds will stick to the 4.1 
branch.
> Since there's no libvirt support in that build, I had to uninstall the
> existing virt-* tools too, therefore no helpers to create a new domU.
> However, a link on LWN reminded me of http://boot.fedoraproject.org/
> and I wondered if I could use that to get a new domU installed.

You could try the virt preview repository
http://fedoraproject.org/wiki/Virtualization_Preview_Repository

That looks like it has a F17 build of the latest F18/F19 libvirt which 
disables the libxl driver so it doesn't conflict with xen-4.2

Michael Young

[Andy Burns]

On 1 November 2012 11:22, M A Young  wrote:
> Note there are now official xen-4.2.0 packages for F18 and F19. They should
> rebuild on F17, though offical F17 builds will stick to the 4.1 branch.

Wasn't expecting F17 to bump to 4.2 at this stage, I'll either rebuild
the F18 packages or upgrade to F18 depending on how soon I reboot the
dom0
> You could try the virt preview repository
> http://fedoraproject.org/wiki/Virtualization_Preview_Repository
>
> That looks like it has a F17 build of the latest F18/F19 libvirt which
> disables the libxl driver so it doesn't conflict with xen-4.2

On F16 xl was "recommended" but caused me problems, so I stuck with
xm, then with Xen 4.2 xl was "really recommended" an I had a problem
with xm, so I switched to xl and my previous problems were indeed
fixed, apart from libvirt not talking to xl yet

I'll probably leave the dom0 up for a few weeks and try F18 with the
updated libvirt at that stage.

[Zhiqiang Ma]

On Thu, Nov 1, 2012 at 3:53 PM, Andy Burns  wrote:
> After installation completed, I edited the .cfg file to change the
> domU from a HVM to a PV, give it a persistent MAC address, steal some
> memory from it and remove the CD drive

If you like, you can also install Fedora 17 DomU in PV mode. I made
the PXE image book by adding some parameters to extra:
http://www.fclose.com/b/linux/3829/installing-fedora-17-domain-u-on-xen-with...

Thanks,
Zhiqiang Ma