Hi Johnny - Yipes, I hate problems like this! The host computer is a SuperMicro C2SBC-Q mainboard. The processor is an Intel Core2-Quad Q9400. Yes, it is x86_64 architecture. The display adapter is an older nVidia GeForce 8400 GS, and I use the nouveau driver for it. Selinux is disabled. The guest machines are Fedora 37 and CentOS7. So far I have found no log files with anything useful. The hang happens so quick that nothing gets logged. Here is a section of /var/log/messages. Notice the gap at 06:32 to 06:43. This is where I started a virtual guest and the system hung. At reboot I chose a different kernel. ====================== Dec 20 06:32:26 practice7 systemd: Starting Fingerprint Authentication Daemon... Dec 20 06:32:26 practice7 dbus[750]: [system] Successfully activated service 'net.reactivated.Fprint' Dec 20 06:32:26 practice7 systemd: Started Fingerprint Authentication Daemon. Dec 20 06:32:26 practice7 dbus[750]: [system] Activating via systemd: service name='org.freedesktop.realmd' unit='realmd.service' Dec 20 06:32:26 practice7 systemd: Starting Realm and Domain Configuration... Dec 20 06:32:26 practice7 dbus[750]: [system] Successfully activated service 'org.freedesktop.realmd' Dec 20 06:32:26 practice7 systemd: Started Realm and Domain Configuration. Dec 20 06:32:48 practice7 systemd: Starting Stop Read-Ahead Data Collection... Dec 20 06:32:48 practice7 systemd: Started Stop Read-Ahead Data Collection. Dec 20 06:43:08 practice7 journal: Runtime journal is using 8.0M (max allowed 391.0M, trying to leave 586.5M free of 3.8G available → current limit 391.0M). Dec 20 06:43:08 practice7 kernel: microcode: microcode updated early to revision 0xa0b, date = 2010-09-28 Dec 20 06:43:08 practice7 kernel: Initializing cgroup subsys cpuset Dec 20 06:43:08 practice7 kernel: Initializing cgroup subsys cpu Dec 20 06:43:08 practice7 kernel: Initializing cgroup subsys cpuacct Dec 20 06:43:08 practice7 kernel: Linux version 3.10.0-1160.76.1.el7.x86_64 (mockbuild at kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (GCC) ) #1 SMP Wed Aug 10 16:21:17 UTC 2022 ========================== Is there anyplace else I should look for log files? Is there a way to get verbose logging? How might I check for a kernel panic? The display never says anything about a kernel panic - it just hangs. Thanks! =============== Bill Gee On 12/20/22 07:25, Johnny Hughes wrote: > On 12/20/22 06:50, Bill Gee wrote: >> The two latest kernels for CentOS7 are complete fails for running KVM >> and QEMU guest machines. >> >> Version 3.10.0-1160.76.1 works correctly. Both 3.10.0-1160.80.1 and >> 3.10.0-1160.81.1 will hang within seconds of launching any virtual >> machine. It is a HARD hang. I have to pull the power cord from the >> computer in order to regain control. >> >> Since 81.1 came out within the last few days, I assumed it would >> contain a fix for this problem. It does not. >> >> Does anyone know when a kernel will be released that fixed this problem? >> > This is not true for all KVM guests. This kernel is actually installed > and test booted before release on a cold iron, KVM VM, Virtual Box VM, > and ESXi VM. > > It also passes our t_functional test suite: > > > > All C7 updates run through all these tests for all new rpms. > > So this problem has some other specific cause. Is this on a E5507 > processor? > > What OS is the KVM host running. I assume this is x86_64 arch? > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos