[Pkg-xen-devel] Bug#880554: Bug#880554: Bug#880554: xen domu freezes with kernel linux-image-4.9.0-4-amd64

[Christian Schwamborn]

I much appreciate the effort you all did and like the idea to ship the 
xen-diag tool and maybe a hint somewhere about the issues that occurred 
and the possible solution by raising max_nr_frames.

On 27.02.2018 17:05, Hans van Kranenburg wrote:
> ad 1. Christian, Valentin, can you give more specific info that can help
> someone else to set up a test environment to trigger > 32 values.

As this isn't my own system, but a productive system of one of my 
customers, I'm really reluctant to use it for invasive testing.

Just for recap: The issues hit me with kernel 4.9.51-1

hardware:
xeon E5-2620 v4
board supermicro X10SRi-F
32gb ecc ram
two 10tb server disk
two I350 network adapter (onboard)

dom0:
debian stretch (up to date), kernel 4.9.51-1, xen-hypervisor 4.8.1-1+deb9u3,
the two network as adapter as a bond in a bridge
the discs: gpt, 4 part (1M, 256M esp, 256M md mirror for boot, rest as 
md mirror for lvm)

domu:
memory: 8192, 2 vcpus
uses a network interface on the bridge
16 lvm volumes as phys devices
debian stretch
issue with both kernel versions: 4.9.30-2+deb9u5 and 4.9.51-1
system runs mostly some smb, some web services, cal/card dav, psql, 
ldap, postfix, cyrus ...

In my early tests before the issue was discussed here I tried 
linux-image-4.13.0-0.bpo.1-amd64 an the system went stable for a week.

Oh and It's worth to mention that I tried thin lvm in the beginning, but 
I dropped that due to (write)performance and boot issues (thinpool was 
always inactive after boot and took about 5-10 minutes to activate after 
there where about 4TB of data within).

currently the system is running stable with max_nr_frames=256 (I wanted 
to be on the save side) and kernel 4.9.65-3+deb9u2.

Maybe I can try to get some values with xen-diag Valentin provided to 
see the current state of the system, but I'm really busy at the moment 
job wise and private, I hope next week gets better (had some bad luck 
with our water installation - much mopping).