Comment 15 for bug 1799497

To add a bit more detail (maybe unrelated but with so little evidence everything helps), when thos lockups happen, is the server at least pingable? Some other idea would be, as long as those servers are accessible enough to see whether sysrq combinations are still handled. Though I fear at least for Stéphane that server is somewhere else with probably only ssh (maybe ipmi) access. But if that was possible and working, maybe one could prepare kdump and enable the sysrq crashing combo.

Otherwise, and that again is probably only possible for Luis if his devel servers do not need zfs, it would help to see how various mainline kernels between 4.4 and 4.15 are doing. And in parallel have some "canary" using the latest update. IIRC the one just released had a large portion of upstream stable pulled in.