On Mon, Feb 17, 2020 at 6:39 PM Glen <glenbarney@gmail.com> wrote:
Dear OpenSuse Team: On Thu, Feb 13, 2020 at 12:44 PM Glen <glenbarney@gmail.com> wrote:
Problem: Xen DomU guests randomly stall under high network/disk loads. Dom0 is not affected. Randomly means anywhere between 1 hour and 14 days after guest boot - the time seems to shorten with (or perhaps the problem is triggered by) increased network (and possibly disk) activity. With that in mind, the best fix so far seems to be to add "sched=credit" to GRUB_CMDLINE_XEN in /etc/default/grub, as in: GRUB_CMDLINE_XEN="dom0_mem=4G dom0_max_vcpus=4 dom0_vcpus_pin gnttab_max_frames=256 sched=credit" Adding that last parameter causes Xen to boot with the older "credit scheduler" instead of the newer "credit2 scheduler", and that seems to resolve the problem for everyone. (I'm still running longer stress tests on my guests, but the results are encouraging so far.)
It's been a week, during which I've stress-tested a number of guests on OpenSuse 15.1 + Xen 4.12.1 + boot option sched=credit . All guests survived without any issue at all. Others on the Xen lists are reporting similar successes. I've completed my client migration, and those guests are also surviving nicely. So I"m tagging this [SOLVED] and tossing in a few subject line keywords for the archives, to help other find this, and I've now brought back one of my (no longer in use) hosts to credit2 so I can start crashing that guest and hopefully capturing debugging information from it. I'll report that data directly to xen-devel since that seems to not be an OpenSuse problem. Apart from OpenSuse possibly making "sched=credit" a Xen boot default now, via an update or whatever, there is one other small item of interest for this group. It has been suggested ( https://lists.xenproject.org/archives/html/xen-users/2020-02/msg00052.html ) that Xen 4.12.2 contains fixes to these and other problems. I do not know how these things work within OpenSuse, but I wonder if bringing in Xen 4.12.2 as an update to OpenSuse 15.1 might be a useful thing to do? I through that out there for all of you who know much more about these things than I. Anyway, I expect this to be my last message on this topic to this group, but wanted to thank all of you who responded to me over the past months again for your help and patience. Everyone is busy, and I was and am very grateful for your time! Best regards, Glen -- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org