Public bug reported: It happened like this:
using kernel 3.13.0-144 (14.04) - ok jun 9: installed kernel 3.13.0-149 and rebooted - ok jun 21: installed some updates including update to the cpu microcode which was set up to execute at the next boot jun 28: rebooted to the same kernel 149 and the system went into cyclic reboot: shows grub screen, when the default kernel is selected reboots immediately with no messages and without creating any logs, nothing in /var/log with appropriate times booted to 144 - no issues tried upgrading to a new kernel (151) - same cyclic reboot booted back to 144 I am not telling the microcode update is the culprit, but it is mighty suspicious. It cannot be uninstalled using standard tools without uninstalling the kernels packages (linux-generic, linux-image-generic, linux-generic-pae, linux-image-generic-pae). I have both intel-microcode and amd64-microcode installed (CPU is AMD phenom X4 975). ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: xorg 1:7.7+1ubuntu8.1 ProcVersionSignature: Ubuntu 3.13.0-144.193-generic 3.13.11-ckt39 Uname: Linux 3.13.0-144-generic i686 NonfreeKernelModules: nvidia ApportVersion: 2.14.1-0ubuntu3.29 Architecture: i386 Date: Thu Jun 28 13:04:38 2018 InstallationDate: Installed on 2011-08-18 (2505 days ago) InstallationMedia: Kubuntu 11.04 "Natty Narwhal" - Release i386 (20110427) SourcePackage: xorg Symptom: display UpgradeStatus: Upgraded to trusty on 2014-10-18 (1349 days ago) ** Affects: xorg (Ubuntu) Importance: Undecided Status: New ** Tags: apport-bug i386 trusty -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1779092 Title: cyclic reboot with latest kernels possibly related to the cpu microcode updater To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1779092/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp