I''ve had a lot of problems with Fedora 7 and XEN and I''ve read some messages on this mailing list indicating the F7 kernel is more or less broke with xen. By problems I mean that 32 bit guests on 64 bit dom0 does not work at all for me. Neither paravirtualized (as was a main feature of xen 3.1) or fully virtualized. Combinations I''ve tried: F7 x86_64 dom0 -> F7 x86 domU PV F7 x86_64 dom0 -> F7 x86 domU HVM RHEL 5 x86_64 dom0 -> F7 x86 domU HVM RHEL 5.1 Beta x86_64 dom0 -> F7 x86 domU PV RHEL 5.1 Beta x86_64 dom0 -> F7 x86 domU HVM RHEL 5 x86 dom0 -> F7 x86 domU PV -- Only one that works (32 on 32 PV) I had read a while ago (June?) that a kernel update would be coming soon to fix the 32 on 64 PV issue, however I''ve ran in several new kernels and none seem to fix the issue. https://www.redhat.com/archives/fedora-xen/2007-June/msg00031.html I''ve also repeatedly tried to run a 32 bit HVM fedora 7 guest on 64 bit machines and had that fail similar to this: http://www.redhat.com/archives/fedora-xen/2007-June/msg00094.html Is there any more work planned for Fedora 7 and xen, or should I just wait until F8? Or am I just doing something wrong and the problems I''m having should be working on the current builds? IMPORTANT: This transmission is sent on behalf of Knouse Foods® for business purposes. It is for the intended recipient only. If you are not the intended recipient or a person responsible for delivering this transmission to the intended recipient, you may not disclose, copy or distribute this transmission or take any action in reliance on it. If you received this transmission in error, please notify us immediately by replying to this Email message, and please dispose of and delete this transmission. Thank you.
On Tue, Sep 25, 2007 at 04:17:24PM -0400, Jason Solan wrote:> I''ve had a lot of problems with Fedora 7 and XEN and I''ve read some > messages on this mailing list indicating the F7 kernel is more or less > broke with xen. > By problems I mean that 32 bit guests on 64 bit dom0 does not work at > all for me. Neither paravirtualized (as was a main feature of xen 3.1) > or fully virtualized.The release notes associated with Xen 3.1 turned out to be not quite accurate on the subject of 32-on-64 & we didn''t realize this when we made corresponding release notes for Fedora 7. Xen 3.1 lets you run a 32-bit DomU kernel on a 64-bit hypervisor + Dom0 *ONLY IF* the DomU kernel was also based on Xen 3.1. ie, a 32-bit DomU kernel based on older Xen 3.0.* release would will not work on Xen 3.1 Unfortunately all the Fedora kernels for FC6 are 3.0.3 and F7 GA was based on Xen 3.0.4, so neither will work on a Xen 3.1 hypervisor + Dom0. In the current Xen-unstable upstream (which will become Xen 3.2) there is now back-compat support for running older DomU kernels. In the most recent update of Xen in F-7 updates-testing we have included a handful of backports which at least let us boot a 32-bit FC6 and F7 domU installer kernel on a 64-bit F7 / F8 host. There are ongoing fixes in upstream Xen for various stability issues when running 32-on-64 though, so it is not perfect. You may be lucky with our latest updates and have it work, but equally you may not be lucky. We''re tracking upstream & will pull in fixes when available.> Combinations I''ve tried: > F7 x86_64 dom0 -> F7 x86 domU PVWorks in basic testing. Has stability problems.> F7 x86_64 dom0 -> F7 x86 domU HVMF7 HVM has been broken since GA for reasons unrelated to the 32-on-64 stuff. A last minute clock-source & bootloader change screwed things up. Yesterday we pushed newer kernel-xen and xen RPMs to updates-testing which hopefully make this work.> RHEL 5 x86_64 dom0 -> F7 x86 domU HVMNot going to work - missing the fix I mention above.> RHEL 5.1 Beta x86_64 dom0 -> F7 x86 domU PVWorks for me, at least to boot the installer. There are sometimes some stability issues though, since Xen 3.1 was far from complete in its 32-on-64 support.> RHEL 5.1 Beta x86_64 dom0 -> F7 x86 domU HVMNot going to work - missing the fix I mention above.> RHEL 5 x86 dom0 -> F7 x86 domU PV -- Only one that works (32 on 32 PV)Matched 32-on-32 and 64-on-64 kernels have always worked.> I had read a while ago (June?) that a kernel update would be coming soon > to fix the 32 on 64 PV issue, however I''ve ran in several new kernels > and none seem to fix the issue. > https://www.redhat.com/archives/fedora-xen/2007-June/msg00031.htmlThe fix required both kernel-xen & xen updates which are finally available in updates-testing.> I''ve also repeatedly tried to run a 32 bit HVM fedora 7 guest on 64 bit > machines and had that fail similar to this:F7 HVM guests have known issues, also hopefully now fixed.> http://www.redhat.com/archives/fedora-xen/2007-June/msg00094.html > > Is there any more work planned for Fedora 7 and xen, or should I just > wait until F8? Or am I just doing something wrong and the problems I''m > having should be working on the current builds?Fedora 7 will continue to have updates until its end-of-life. The issue is that even in upstream Xen 32-on-64 doesn''t have the same level of stability as 32-on-32, or 64-on-64. Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|
Thank you for the detailed and full explanation. I appreciate all the work the Fedora and Red Hat teams have done with the XEN development. I was just very surprised(and frustrated) that a fully virtualized F7 would not work. We have implemented a couple of small domU''s (webservers,ntp,etc) on a RHEL 5 32-bit dom0. We were looking for a way to move the vm''s to some of our more powerful 64-bit machines. Some of the domU''s where FC6 and they worked perfectly in HVM mode. Others were F7 and we were unable to do anything with them. Looking forward to trying out the newer kernels (as well as the RHEL 5.1 release). Again, thanks for the information, its nice to see it all very clearly explained out in one place. On Thu, 2007-09-27 at 05:22 +0100, Daniel P. Berrange wrote:> On Tue, Sep 25, 2007 at 04:17:24PM -0400, Jason Solan wrote: > > I''ve had a lot of problems with Fedora 7 and XEN and I''ve read some > > messages on this mailing list indicating the F7 kernel is more or less > > broke with xen. > > By problems I mean that 32 bit guests on 64 bit dom0 does not work at > > all for me. Neither paravirtualized (as was a main feature of xen 3.1) > > or fully virtualized. > > The release notes associated with Xen 3.1 turned out to be not quite > accurate on the subject of 32-on-64 & we didn''t realize this when we > made corresponding release notes for Fedora 7. > > Xen 3.1 lets you run a 32-bit DomU kernel on a 64-bit hypervisor + Dom0 > *ONLY IF* the DomU kernel was also based on Xen 3.1. ie, a 32-bit DomU > kernel based on older Xen 3.0.* release would will not work on Xen 3.1 > Unfortunately all the Fedora kernels for FC6 are 3.0.3 and F7 GA was > based on Xen 3.0.4, so neither will work on a Xen 3.1 hypervisor + Dom0. > > In the current Xen-unstable upstream (which will become Xen 3.2) there > is now back-compat support for running older DomU kernels. In the most > recent update of Xen in F-7 updates-testing we have included a handful > of backports which at least let us boot a 32-bit FC6 and F7 domU installer > kernel on a 64-bit F7 / F8 host. > > There are ongoing fixes in upstream Xen for various stability issues > when running 32-on-64 though, so it is not perfect. You may be lucky > with our latest updates and have it work, but equally you may not be > lucky. We''re tracking upstream & will pull in fixes when available. > > > Combinations I''ve tried: > > F7 x86_64 dom0 -> F7 x86 domU PV > > Works in basic testing. Has stability problems. > > > F7 x86_64 dom0 -> F7 x86 domU HVM > > F7 HVM has been broken since GA for reasons unrelated to the 32-on-64 > stuff. A last minute clock-source & bootloader change screwed things > up. Yesterday we pushed newer kernel-xen and xen RPMs to updates-testing > which hopefully make this work. > > > RHEL 5 x86_64 dom0 -> F7 x86 domU HVM > > Not going to work - missing the fix I mention above. > > > RHEL 5.1 Beta x86_64 dom0 -> F7 x86 domU PV > > Works for me, at least to boot the installer. There are sometimes some > stability issues though, since Xen 3.1 was far from complete in its > 32-on-64 support. > > > RHEL 5.1 Beta x86_64 dom0 -> F7 x86 domU HVM > > Not going to work - missing the fix I mention above. > > > RHEL 5 x86 dom0 -> F7 x86 domU PV -- Only one that works (32 on 32 PV) > > Matched 32-on-32 and 64-on-64 kernels have always worked. > > > I had read a while ago (June?) that a kernel update would be coming soon > > to fix the 32 on 64 PV issue, however I''ve ran in several new kernels > > and none seem to fix the issue. > > https://www.redhat.com/archives/fedora-xen/2007-June/msg00031.html > > The fix required both kernel-xen & xen updates which are finally available > in updates-testing. > > > I''ve also repeatedly tried to run a 32 bit HVM fedora 7 guest on 64 bit > > machines and had that fail similar to this: > > F7 HVM guests have known issues, also hopefully now fixed. > > > http://www.redhat.com/archives/fedora-xen/2007-June/msg00094.html > > > > Is there any more work planned for Fedora 7 and xen, or should I just > > wait until F8? Or am I just doing something wrong and the problems I''m > > having should be working on the current builds? > > > Fedora 7 will continue to have updates until its end-of-life. The issue > is that even in upstream Xen 32-on-64 doesn''t have the same level of > stability as 32-on-32, or 64-on-64. > > Dan.IMPORTANT: This transmission is sent on behalf of Knouse Foods® for business purposes. It is for the intended recipient only. If you are not the intended recipient or a person responsible for delivering this transmission to the intended recipient, you may not disclose, copy or distribute this transmission or take any action in reliance on it. If you received this transmission in error, please notify us immediately by replying to this Email message, and please dispose of and delete this transmission. Thank you.