[fedora-virt] Fedora 12 Xen guests (domU) and hosts (dom0)
pasik at iki.fi
Fri Jan 15 13:39:14 UTC 2010
On Fri, Jan 15, 2010 at 01:54:09PM +0200, Pasi Kärkkäinen wrote:
> I thought of writing some information about running Fedora 12 Xen guests
> and also Fedora 12 Xen hosts/dom0.
> Fedora 12 includes the upstream Linux pv_ops Xen domU support in the default kernel.
> By using virt-install or virt-manager you can install Fedora 12 Xen PV
> (paravirtual) guests directly from network, for example on RHEL 5.4,
> CentOS 5.4, or Fedora Xen dom0/host.
> If you want to run Fedora 12 Xen dom0 (host), there are some extra steps
> needed. Fedora 12 ships with Xen hypervisor and management tools
> (Xen 3.4.1, and Xen 3.4.2 in the F12 updates), but the required Xen dom0
> capable host kernel is not included in Fedora atm/yet.
> General information about Xen dom0 status in Fedora:
> There are a couple of different ways to get and install a Xen dom0
> capable kernel to Fedora 12 host:
> - By using pre-packaged pv_ops xendom0 kernel rpms by M A Young. his repository:
> - Compiling and installing Xen dom0 capable kernel yourself/manually.
> There are many options to choose from, full list of the available Xen
> dom0 capable kernels is here:
> The recommended dom0 kernel is the pv_ops kernel, which is in the
> process of being cleaned up for upstream/mainline Linux inclusion.
> More information about pv_ops dom0 kernel, including the status
> Xen developers are interested of both the success and failure reports
> when using the Xen pv_ops dom0 kernel.
> Tips for running Xen with Fedora 12:
> - Make sure you install all the latest Fedora 12 updates, since they
> have an updated Xen version (3.4.2), and also fix a bug in
> python-virtinst tool to make Xen guest console keymaps work properly:
> - Recent versions of Xen pv_ops dom0 kernel renamed some xen
> backend driver modules to have "xen-" prefix in them, for
> example evtchn module became xen-evtchn. Fedora Xen 3.4.2 init
> scripts take care of this, and load the correct modules, but
> Xen 3.4.1 doesn't do this automatically, causing xend fail to
> start in dom0/host before the modules are loaded manually.
> - There are some upcoming apic-related changes coming in pv_ops
> dom0 kernel, which will require a patch to Xen hypervisor.
> This patch is not yet included in the Fedora Xen rpms.
> The patch will be added to Fedora Xen rpms when the upstream
> pv_ops kernel starts to require/use it.
> - pv_ops dom0 kernel currently lacks blktap2 support, so using
> tap:aio: backend disk image files is not yet possible.
> Xen file: backend image files work though.
> At the moment it's recommended to use LVM volumes for guest
> disks (Xen phy: backend).
> - virt-manager seems to work OK on Fedora 12 Xen dom0.
> - If you experience problems related to Fedora 12 guests (domU)
> kernel crashing (especially related to save/restore/migration),
> install the latest Fedora updates to the guest. There has been
> a lot of Xen guest related fixes in the upstream Linux recently.
> These fixes will appear in Fedora when the kernel gets updated
> to include the latest stable upstream fixes.
Replying to myself again.. I forgot one thing from the list of tips:
- Disable selinux from /etc/selinux/config to make it easier to
use custom directories for storing Xen guest image files and
prevent other problems from happening.
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