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Re: [Xen-users] The death of XEN by Novell

Mark Williamson schrieb:
On Sunday 20 July 2008, jim burns wrote:
On Sun July 20 2008 9:51:52 am Venefax wrote:
The Novell engineer showed me a technical document, which I did not write
the number, on the Novell web site, where it said: windows SMP using the
Novell driver crashes.
That's what I thought - the problem is with Novell's PV drivers, not Xen.
James had some initial problems with SMP also.

Right, that's important. Novell's PV drivers are their code so those drivers might have limitations that plain Xen does not. Presumably it would be possible to run using fully emulated IO instead of PV drivers but I imagine this could have performance problems in your configuration. Could be worth a try, if you can afford to experiment.

If the Windows VMs themselves are crashing due to Novell's PV drivers then I'm afraid this limitation / problem is really Novell's responsibility and they would be the best people to approach for assistance / complaints. The code for those drivers isn't open, so only Novell can fix them. If the Novell PV drivers are somehow crashing your Linux domains or dom0 or Xen itself then that might be a Xen bug and it would be useful to post more details here.

For comparison, Citrix/XenSource supply with their product PV drivers for Windows that are - AFAIK - a different codebase and may not have these limitations. So do Virtual Iron, for their Xen-based product. Both of these can only be used with their respective commercial hypervisors, AFAIK. James Harper's PV drivers for Windows are GPL but still under development and so I doubt they'd be recommended for heavy production use.

There are a lot of different PV driver solutions for Windows about and none of them are officially part of the OSS Xen project; only one of them is even Open Source.

I really wonder why you run your SQL servers in windows and all the rest in Linux??? I asume especially for databases is Windows a bad base, but i have a win20008 sharepoint running on xen 3.2.1 with 2 vcpus it works great and stable with james drives. And if you like to use this single Box, you may ask SUN (Solaris and SunXvm).


 I use a SIP Server on the Linux side, talking hundreds of times per
second to SQL Server, so I need SMP 8 ways on both  ends.
Something I've never seen you actually say is that you *tried* vcpu=1, and
the performance was bad. So far, it sounds like theory to me. Even with 1
vcpu, playing with scheduling weights should help.

Venefax, are you able to try this?

Thank you,

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