[fedora-virt] xen 4.0.0 build/install notes/bugs

[M A Young]

On Tue, 4 May 2010, Bill McGonigle wrote:

> A few issues I hit trying to build/install the latest xen from the myoung 
> dom0 repo:
>
> 1) [root at librescu SPECS]# rpmbuild  -bb xen.spec  kernel.spec
> error: Failed build dependencies:
>        /usr/include/gnu/stubs-32.h is needed by xen-4.0.0-0.7.fc12.src

That is correct, though not as helpful as it might be, because it requires 
the file rather than the package. That is something from the existing 
Fedora xen package I didn't change.

> 3) During xen RPM install:
>
> Stopping xend daemon: [  OK  ]
> Starting xend daemon: [FAILED]
> warning: %post(xen-4.0.0-0.7.fc12.x86_64) scriptlet failed, exit status 1
>
> log says:
>
> [2010-05-04 12:41:32 23773] ERROR (SrvDaemon:356) Exception starting xend 
> ((38, 'Function not implemented'))
> Traceback (most recent call last):
>  File "/usr/lib64/python2.6/site-packages/xen/xend/server/SrvDaemon.py", 
> line 342, in run
>    xinfo = xc.xeninfo()
> Error: (38, 'Function not implemented')
>
> It looks like a xend restart can't happen from 3->4, so perhaps just handle 
> the upgrade scenario gracefully?  xend starts fine after a reboot, but we 
> shouldn't kick out in %post.

I don't have any say over the Fedora xen package (I am just sharing stuff 
I have done for my own use that others might find useful as well) but I 
suspect that Fedora releases would stick to either 3.4.x or 4.0.x so the 
only time you would upgrade from 3.4.x to 4.0.x would be when you were 
going between Fedora versions, for which the recommended way would be to 
use the standard install/upgrade process where you would be booted off the 
install image. Hence you would tune the system to support minor upgrades 
(eg 3.4.2 to 3.4.3) where restarting xend probably does make sense, with 
the 3.4.x to 4.0.x upgrade being much less important because you wouldn't 
be doing that live in the recommended course of events.

It is worth noting the issue though in case xen 4.0.x is released for F12 
or F13.

> 4) grub not properly updated

Full grub support is on the TO DO list when Fedora supports xen dom0 
again, though this is unlikely to happen before dom0 support is back in 
the upstream linux kernel. At the moment you have to configure it 
manually.

> 5) qemu-dm moved from /usr/lib64 to /usr/lib - dunno if this is correct, if I 
> have the right version, etc.

Yes, that does look like it might be a bug. The upstream file seems to 
have moved between 3.4 and 4.0 but it might make sense to move it back, 
either within Fedora or with an upstream patch for Fedora builds. Of 
course there might have been a good reason why it was moved, in which it 
would make sense to leave it.

 	Michael Young