Public bug reported: This bug may be a duplicate of https://bugs.launchpad.net/ubuntu/+source/dnsmasq/+bug/1688364 but I'm not sure, hence this new entry.
It hits while I wanted systemd to resolve the lxc domain to my internal lxc hosts. Step to (maybe) reproduce: - having lxc installed - make some user space lxc container - uncomment the line LXC_DOMAIN="lxc" in /etc/default/lxc-net - restart lxc-net service Now the dnsmasq on 10.0.3.1 should be a dns resolving lxc names. - add a file /etc/systemd/resolved.conf.d/lxc.conf [Resolve] DNS=10.0.3.1 Domains=~.lxc DNSSEC=false - restart systemd-resolved service Now systemd knows it should ask .lxc names to dnsmasq - start an lxc container, let assume it's called my-container - ping it using my-container.lxc it should work After some times, systemd-resolved should use 100% CPU. Commenting the /etc/systemd/resolved.conf.d/lxc.conf file and restarting it makes systemd-resolved never eating resources again. ProblemType: Bug DistroRelease: Ubuntu 17.04 Package: systemd 232-21ubuntu5 Uname: Linux 4.10.16-041016-generic x86_64 ApportVersion: 2.20.4-0ubuntu4.5 Architecture: amd64 CurrentDesktop: GNOME Date: Tue Oct 3 18:18:56 2017 InstallationDate: Installed on 2015-11-10 (692 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021) MachineType: Intel Corporation Skylake Platform ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.10.16-041016-generic root=UUID=6814e3c1-8cea-4ecc-964d-535fd18782e9 ro quiet splash crashkernel=384M-:128M vt.handoff=7 SourcePackage: systemd UpgradeStatus: Upgraded to zesty on 2017-02-25 (219 days ago) dmi.bios.date: 11/06/2015 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 5.11 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: WhiteTip Mountain1 Fab2 dmi.board.vendor: Topstar dmi.board.version: RVP7 dmi.chassis.asset.tag: Default string dmi.chassis.type: 9 dmi.chassis.vendor: Default string dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr5.11:bd11/06/2015:svnIntelCorporation:pnSkylakePlatform:pvr0.1:rvnTopstar:rnWhiteTipMountain1Fab2:rvrRVP7:cvnDefaultstring:ct9:cvrDefaultstring: dmi.product.name: Skylake Platform dmi.product.version: 0.1 dmi.sys.vendor: Intel Corporation ** Affects: systemd (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug zesty -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1721092 Title: systemd-resolved and dns-masq make CPU 100% when using lxc name resolution To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1721092/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs