Sep 202012

I’ve just pushed out new Xen 4.2.0 RPMs to the repo. They should start syncing in the near future.

I recommend that you shut down all running DomUs before upgrading the Xen packages as due to the toolset changes, you may not be able to do it AFTER upgrading.

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  16 Responses to “Xen 4.2.0 packages pushed to the repos.”

  1. xen 4.2 update seems to have gone fairly smoothly. backwards compatibility with xm seems to work fine, and our Cloudmin management systems are not complaining.

    However the attempt to upgrade to 3.5.X kernels didn’t go so well, after update:

    # xm list
    Error: Unable to connect to xend: No such file or directory. Is xend running?

    Rebooted with the 2.6.X kernel and it works fine.

    When I have some time I will install on a test server and try to get it working… Are you aware of any changes that need to be made to any config files or init scripts?

    • Hi Chris,

      Usually this is caused by forgetting to load the hypervisor before the kernel in /etc/grub.conf. By default, after a kernel update, you need to manually add the xen.gz line. I’m looking for a way to automatically do this, but for now this is a manual step.

  2. Silly me, should have known to check that. Just tested one machine with 3.5.4-2.el6xen and xen-4.2.0 and it’s working nicely. Thanks!

    Will leave one machine running this config for a few days to make sure it’s stable, then update the whole pool. We currently have 10 machines running your xen kernel & tools on CentOS 6.

  3. Dear Steven,

    I have updated Xen to version 4.2.0 with your packages, but I am having issues with libvirt. In order to make libvirt work I patched and recompiled the source RPM without issues for the previous Xen version you uploaded. But with version 4.2.0 no machines are listed when I issue the command “virsh list”.

    Has anybody experienced the same issue?


  4. Hi Jordi,

    libvirt is not required at all to use Xen. You should be using xm or xl for DomU management. The ‘compatible’ way to use these tools for EL6 is xm, which is the default – however you can also use the xl tool.

    As such, replace virsh list with xm list.

  5. Hi Steven,

    The point of using virsh is to allow the graphical application Virtual Machine Manager (virt-manager) to work. Is there any equivalent option to remotely manage, as well as access, the different guests?


    • Hi Jordi,

      I understand the point of using libvirt, however it is not part of the Xen project. As it is a seperate tool by a completely different group, it may take them some time to build a usable libvirt for Xen 4.2.0.

      I would suggest talking to the libvirt people on estimates for compatibility to Xen 4.2.0 by one of the methods listed on their site:

  6. Ah OK. I though it was compatible with Xen 4.2.0 and there was some compilation flag not set, that is why I was asking you.

    By the way, regarding the Virtual TPM, this is not enabled by default in Xen 4.2.0. But it seems that enable it is not trivial, since it requires an old and tweaked Linux kernel (2.6.18) that it is not easy to find.

    Thanks for your responses Steven!

  7. Hi Steven and Jordi,

    actually the ‘compatible’ way to use any hypervisor on RHEL and Fedora is exactly libvirtd, not to mention the fact that libvirtd was once started as a project around the Xen hypervisor, but that is semantics and is not really important.

    What is important is that with the version bump to 4.2.0 libxenlight is completely incompatible with the current abstraction in libvirtd and from what is available both in the source tree of libvirtd and Xen, it seems that it will be a long time since we have libvirtd working with Xen > 4.1. The weird thing is that according to Xen developers the main reason why the libxl was redone the way it is in 4.2 is because of libvirtd.

    So Jordi, if you are like me and a bunch of other people around and you have the hyperversity syndrome — with KVM, Xen and LXC in my case — and wish to stick to a single point of management it’s just not gonna happen with libvirtd, at least not soon.

  8. Hi Steve,

    Thanks for this repo, it’s pretty good, I’d like to know if/where I could get a hold of the previous version of your work (Xen 4.1.3), the reason is I’m using this as a proof of concept for a GPU-clodu (using openstack). Basically, an openstack cloud, using libvirt and Xen 4.1.3 from your repo, it worked pretty good until the repo changed to 4.2.0. Like you well know libvirt is not working properly with Xen 4.2 but it is was is being used in my openstack setup so I would really like to finish the POC with your previous release (Xen 4.1.3).

    Would it be possible to get access to a snapshot of the repo as it was before Sep 20th? I would make a copy and use it for the timeframe of the project.


  9. Hi Boris,

    I’m restoring the Xen 4.1.3 SRPM from a backup which will allow me to build the x86_64 packages and i386 packages from it again.

    I’ll see if I can put them back in the repo as an old version – however they probably won’t receive any update love. Hopefully, the libvirt guys can fix this quickly for those stuck on 4.1.3…

    EDIT: In fact, this may actually be a better option:

    There is a patch for libvirt that *may* fix the compile issues against Xen 4.2. If anyone is able to test it, this would be great.

  10. Hi Steven

    i’m update 4.1.3 to 4.2,xen pv can’t create ubuntu and fedora guest os,other OS is fine.

    # xm create -c /etc/xen/auto/ubuntu.cfg
    Using config file “/etc/xen/auto/vm1470.cfg”.
    Using to parse /boot/grub/menu.lst

    Started domain ubuntuos (id=XXX) [the here have exit out]

  11. Hey Steve,
    The libvirt patch provided did not work. I also tried with a compile from nightly snapshot which includes that patch and still fails.

    In file included from libxl/libxl_conf.c:43:
    libxl/libxl_conf.h:61: error: field 'ctx' has incomplete type
    libxl/libxl_conf.h:80: error: field 'ctx' has incomplete type
    libxl/libxl_conf.h:81: error: expected specifier-qualifier-list before 'libxl_waiter'
    libxl/libxl_conf.c:889: error: used struct type value where scalar is required
    libxl/libxl_conf.c:906: warning: implicit declaration of function 'libxl_device_model_info_destroy' [-Wimplicit-function-declaration]
    libxl/libxl_conf.c:906: warning: nested extern declaration of 'libxl_device_model_info_destroy' [-Wnested-externs]
    libxl/libxl_conf.c: In function 'libxlBuildDomainConfig':
    libxl/libxl_conf.c:973: warning: implicit declaration of function 'libxl_domain_config_destroy' [-Wimplicit-function-declaration]
    libxl/libxl_conf.c:973: warning: nested extern declaration of 'libxl_domain_config_destroy' [-Wnested-externs]
    At top level:
    cc1: warning: unrecognized command line option "-Wno-suggest-attribute=const"
    cc1: warning: unrecognized command line option "-Wno-suggest-attribute=pure"
    make[3]: *** [libvirt_driver_libxl_impl_la-libxl_conf.lo] Error 1
    make[3]: *** Waiting for unfinished jobs....

    • Thanks Wayne,

      I figured that might be the case. Its partly why I prefer not to rely on any third party tools like libvirt. It makes life easier in some cases, but in others can make things much worse. This is one of those cases.

      I’m awaiting some feedback on some Xen 4.2 packages I created for EL5 x86_64 and if all goes well, I’ll resync my dev tree to the repos which will bring back Xen 4.1.3 for those stuck with relying on libvirt. The good news is hopefully it will mean 1 x SRPM will build on both EL5 and EL6. I’d also like the thank the sponsor that donated to my Xen development by providing me with new hard drives. They are the reason EL5 packages should appear in the near future. I haven’t named them as yet as I’m not sure if they want to be named or not.

      As I’m not employed full time (and sometimes rarely even casually), sponsorship like this makes a massive difference to what I am able to develop. I should also like to mention the sponsors that provide mirrors for the Xen RPMs. Without them, the bandwidth bill alone would exceed my limited income! Thanks guys.

  12. HI Steve,
    I am following your blogs and articles to build my first XEN on Centos 6.3, and hitting issues. However enjoying every moment.

    I am happy to mirror your binaries etc.
    Please email me directly and we will take it forward

    Keep up the good work!

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