On Mon, Apr 30, 2018 at 1:08 PM, Daz Day <dazday60@xxxxxxxxx> wrote: > Hi, > > I've tried hitting up the CentOS forums and thought I'd try here too as I > don't seem to be getting any bites. > > We've been in the process of migrating all our hypervisors over to CentOS 7 > using Xen. Once we had a few up and running we started to notice that the > DomU's would randomly freeze. They become unresponsive to any network > traffic, stop consuming CPU resources on the hypervisor and it's not > possible to log in to the console locally using: > virsh console <domain> > We can sometimes get as far as typing a username and hitting return, but the > DomU just hangs there. It doesn't seem to matter what Linux distro the DomU > is running, it affects them all. The only way we can get them back is by > destroying and recreating them (far from ideal!). > > After a bit of research and digging around, we eventually found these 2 > nuggets: > https://wiki.gentoo.org/wiki/Xen#Xen_domU_hanging_with_kernel_4.3.2B > https://www.novell.com/support/kb/doc.php?id=7018590 > > They both advise adding the command line argument: > gnttab_max_frames=256(the default is 32). > We applied this change and all hypervisors rand stable for around a week > until DomU's started freezing again (we've since tried even higher values, > to no avail). More research later led me to > https://bugs.centos.org/view.php?id=14258 and > https://bugs.centos.org/view.php?id=14284 (which are essentially the same > report). There hasn't really been any movement on these tickets > unfortunately, but I have +1'd them. > > Have any others had issues with Xen and DomU's locking up in CentOS 7? Are > there any other fixes/workarounds? If any additional info is needed that > isn't already in the bug tickets or forum post, please let me know and I'll > be happy to provide whatever is required (these freezes are happening at > least once a day). > > Any help would be much appreciated and would mean my Ops guys could get a > decent sleep! > Cheers > Darren Darren, Would you mind reposting this to xen-users, along with: * The config file for your guests * The output of `dmesg` from inside one of the guests before it hangs * The output of `dmesg` run on your dom0 after one of these machine hangs Thanks, -George _______________________________________________ CentOS-virt mailing list CentOS-virt@xxxxxxxxxx https://lists.centos.org/mailman/listinfo/centos-virt
