Hi
there,
Ever
since all the Meltdown and Spectre kernel updates and possibly
also Xen 4.8 updates, we experience crashes of the Dom0 just
out of the blue. Sometimes after 1 day, sometimes after a few
days or even 14 days, completely random.
We
have two Dell P730 servers and two Dell P720 servers with this
behaviour. One thing is that we updated these machine to the
latest available firmware, because that is the most secure
way. Then we installed Debian Stretch with Xen 4.8 support
We
have done serveral installs and 4 servers seem to crash pretty
fast and other don't. In the end we think that we can lead it
back to the xen-4.8.4-pre version being stable and the
xen-4.8.5-pre being unstable. This was kinda independent of
the kernel that we were using 4.14 or 4.9.0-8-amd64. This is
off course all Debian package numbering.
As
last resort we updated on one server all DomU kernels of our
Jessie servers on this Dom0 to 4.9.0 from backports instead of
the 3.16 kernel. For now that seems to work, but the crashes
are random so it could happen any time again. The idea is that
these kernels are completely spectre& meltdown unaware and
might cause trouble in Xen kernel support. I am not sure if
this is true at all, but we are pretty lost what the actual
cause is.
We
also tested with CentOS and we also had these crashes there
with certain combinations of kernel/Xen. The most recent
updates seem to be more stable tough. The most frustrating
part is the there is absolutely no logs to be found. No kernel
oops or what.. the server just resets and boots again.
Are
there others experiencing problems like this? Do you see more
frequent server/kernel crashes on production servers?
