[CentOS-virt] Building Xen 4.4 rpms for centos7

Tue Jan 20 15:27:48 UTC 2015
Pasi Kärkkäinen <pasik at iki.fi>

On Tue, Jan 20, 2015 at 08:35:31AM -0600, Johnny Hughes wrote:
> On 01/20/2015 08:10 AM, Pasi Kärkkäinen wrote:
> > Hello,
> > 
> > Now that the Xen 4.4.1 rpms + libvirt 1.2.10 rpms for CentOS 6 seem to be in good shape
> > it would be a good time to start experimenting with el7 builds aswell.
> > 
> > I think it's best to start with the same set of packages we have for el6,
> > and just do the minimum required changes to get them working on centos7.
> > 
> > That probably means fixing some dependencies in the spec file, and some changes for systemd support. 
> > 
> > Note that all those changes are already done in Fedora 21 Xen rpms, for example:
> > ftp://ftp.funet.fi/pub/mirrors/fedora.redhat.com/pub/fedora/linux/updates/21/SRPMS/x/xen-4.4.1-12.fc21.src.rpm
> > 
> > A few months ago I also saw a Xen 4.4 el7 rpms port, so we could find those src.rpms aswell.
> > 
> Agreed on this too .. let's use as much the same as we can, and we can
> use %if statements in the SPEC to differentiate el6 and el7 things, if
> necessary.  systemd versus init and maybe some version number changes
> for buildrequires should be the changes we need to be concerned about.

> > 
> > And then there's the dom0 kernel.. Stock rhel7/centos7 is based on Linux 3.10 kernel,
> > so we probably can use the exact same 3.10.63 kernel we have today for CentOS 6 Xen.
> I agree that we can likely use the current centos-6 kernel.  We do need
> to decide when we want to shift the kernel to 3.14 .. the support for
> 3.10 as a LTS kernel ends in September 2015 (so 9 months).
> https://www.kernel.org/category/releases.html
> We can try to take the RH 3.10 el7 kernel, mod it for xen, and use it ..
> or we can shift to 3.14.x and that buys us at least one more year .. or
> wait until they name the next LTS kernel and go for that.  Likely the
> next LTS kernel will be the easiest option (the RH modified kernel will
> not support xen and rolling in stuff externally will be hard because of
> the backports RH does to the kernel (things that go into a standard
> kernel will not apply cleanly to the RH kernel).
> But, I agree lets try to use the el6 kernel for xen el7 too .. and we
> can switch both kernels as required later.

Yeah we're not in a hurry with the dom0 kernel. Current Linux 3.10.x seems to work fine atm.

Let's focus on getting the current rpms built for el7,
and then later we can update both el6 and el7 to later kernel/versions.

-- Pasi