[Xen-users] Re: Issues migrating to xen 4.1

[Mike Fröhner <mikefroehner@xxxxxx>]

Hello,

Am 11.04.2011 03:07, schrieb Sylvain CHEVALIER:
> Many thanks Pasi and Claudiu for helping and sharing.
>
> I am sorry for not giving much more details about our experiences with
> dom0 hanging, but I don't want to touch our server right now as it is
> running fine (except for qemu-dm memory leak) and people are using it.
> I hope to set up another server this week and experiment with it.
> These issues were similar to what Claudu described, but again, after
> applying the fixes I described, it has been working fine, and we did
> not have to revert it to 4.0.
>
> I think we had terminal issues, with any command run locally or
> remotely in dom0 giving an 'input/output' error message), and we could
> not establish any other connection to it.
I got here same Error after upgrading to xen-4.1 using 2.6.38-xen on 
gentoo. There are several domUs (gentoo, ubuntu, windows) running on 
this system it crashes without a kernel panic error just the 
'input/output'-error.
There are 4 NICs bonded to bond0 with 3 VLANs bond0.1, bond0.11, 
bond0.12. The bridges are xvbr1 >> bond0.1, xvbr11 >> bond0.11 and 
xvbr12 >> bond0.12. I DONT use the xen-bridge-script because there is no 
need to build the brigdes. RAM 48GB, 2x quadcore CPU (Intel Xeon).
You said u fixed this issue with crashing, do u remember how? I am not 
really able to get informations out of all these "RE:" messages.
I really would be happy if u could tell me u fixed it.


Regards,
Mike


> We are using the latest kernel on gentoo: 2.6.34-xen-r4 and had
> similar issues with the previous one (2.6.34-xen-r3).
>
> Thanks,
>
> Sylvain
>
> On Mon, Apr 11, 2011 at 3:30 AM, Pasi Kärkkäinen<pasik@xxxxxx>  wrote:
> > On Sun, Apr 10, 2011 at 12:56:05PM +0800, Sylvain CHEVALIER wrote:
> > > Hi,
> > >
> > > We just migrated xen on gentoo on amd64 from 4.0 to 4.1 and
> > > encountered a few issues that were not documented. Here is how we
> > > solved them and what issues are remaining:
> > >
> > > 1. Our config files were referring to the LVM devices like
> > > /dev/vg/domU-root with disk = [ 'phy:vg/domU-root,sda1,w' ]. This does
> > > not work anymore, we have to include '/dev/': disk = [
> > > 'phy:/dev/vg/domU-root,sda1,w' ].
> > Hello,
> >
> > I replied this 1. in another email.
> >
> > > 2. We were using bridges to map the 4 ethernet cards to virtual
> > > machines so that virtual machines could have their own IP addresses.
> > > In xen 4.1, it is recommended to configure bridges by ourselves and
> > > not use xend although xend would still work. We could not get the
> > > bridges to work and went on using xend. However, the network-bridge
> > > script now includes a test: if a bridge already exist, then it would
> > > do nothing. The problem with that is that our wrapper script for
> > > network-bridge would only create the first bridge. So we had to
> > > comment out the test in network-bridge, and it would work. Did anybody
> > > successfully create bridges on gentoo?
> > > Meanwhile, we found that if a domU is started and tries to access a
> > > bridge that does not exist, dom0 would stop working. Shall it be a
> > > bug?
> > What do you mean dom0 would stop working? Network dies?
> > Does it work from the console?
> >
> > And yes, it's recommended to configure networking using the distro
> > network scripts, see here for examples: 
> > http://wiki.xen.org/xenwiki/HostConfiguration/Networking
> >
> >
> > > 3. I believe we have memory issues when running a windows domU. We use
> > > to allocate 512MB to domU and found that qemu would quickly use most
> > > of it and after a while, dom0 would stop working. Now we allocate 4GB,
> > > made sure there is no ballooning and it appears to work fine. Memory
> > > leaks by qemu are widely reported but I wonder why we did not have
> > > such issues before xen 4.1 update.
> > Again what do you mean with dom0 would stop working? dom0 kernel crash? 
> > hypervisor crash?
> > And did you mean qemu-dm process in dom0 is leaking memory?
> >
> > > 4. We might also have issues with CPUs. dom0 and all domU were
> > > authorized to use all CPUs, and we saw the whole system freezing often
> > > and quickly when mounting in charge after the 4.1 update. After we
> > > spinned one CPU to dom0 we haven't seen this issue. Would this be a
> > > bug?
> > This definitely sounds like a bug.
> >
> > Please set up a serial console and capture the error/crash messages:
> > http://wiki.xensource.com/xenwiki/XenSerialConsole
> >
> > Also: what dom0 kernel version are you using?
> >
> > > Any hint or help on finding better solutions would be appreciated
> > -- Pasi


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users