Re: Debian 10, xen 4.11 reliability

[Nick Calvert <nick.calvert@xxxxxxxxx>]

Another blind shot and this may not be very helpful, but I have seen
general instability with 4.11 on certain hardware that was never fully
diagnosed. It appears to be magically resolved on newer versions.

I suspected this: https://xenbits.xen.org/xsa/advisory-294.html at the
time as some silicon was changed (but not underlying hardware
platform), introducing PCID in all cases. I did not prove this and it
was not a denial of service failure mode.

If you can, perhaps building from source or applying that patch could
help. Please let us know how you get on, issues like this are always
very frustrating.

On Tue, 14 Jul 2020 at 15:46, Tomas Mozes <hydrapolic@xxxxxxxxx> wrote:
>
>
>
> On Thursday, July 9, 2020, Casper <kl@xxxxx> wrote:
> > Hello,
> >
> > I have used Debian/Xen dom0 for many years, Debian 7, 3.2.41 kernel with 
> > Xen 4.1.4 on some servers still work very reliable with no problems, only 
> > wanted to change new hard discs pushed me to install new Debian 10 with Xen 
> > packages to newer version.
> >
> > Where I reinstall Debian 10, latest 4.19 kernel it comes with Xen 
> > 4.11.4-pre all crashes in 1-2weeks. In start I was blaming HW, but now it 
> > repeats in old reliable servers too. My config is I have 2-3 hard discs per 
> > server node and RAID1 with sw md raid, it crashes with md lost access for 
> > disc. After reboot all works as it should.
> >
> > I tested different HW and discs, all the same problems.
> > Loads are no big, just few testing DomU nodes.
> > Any suggestion? I`m currently running latest Debian kernel 4.19 was 
> > thinking to downgrade to test different kernel.
> > Or problem with Debian Xen package as it not so popular anymore?
> > Any suggestion what to test to figure out problem?
> >
> > Sincerely,
> > Casper
> >
> >
>
> Just a blind shoot - which scheduler are you using? If credit2, try credit 
> legacy.
>
> https://wiki.gentoo.org/wiki/Xen#Xen_domU_hanging_with_Xen_4.12.2B