OK, I've managed to reproduce this (in a non-Juju launched VM). The ordering of these journal lines look suspicious to me:
Nov 09 17:41:51.091033 ubuntu systemd[1]: Starting udev Coldplug all Devices... Nov 09 17:41:51.236309 ubuntu systemd[1]: Finished Load Kernel Modules. Nov 09 17:41:51.363482 ubuntu systemd[1]: Finished udev Coldplug all Devices. Because, you guessed it, hv_netvsc is shipped as a kernel module: $ lsmod | grep hv_netvsc hv_netvsc 81920 0 So my assumption is that udev coldplugging of the network device is happening before the driver is loaded, and so (unsurprisingly :) it doesn't find the driver. I suspect that adding an `After=systemd-modules-load.service` to systemd-udev-trigger-service addresses the issue, but as this only reproduces on first boot this is difficult to test. Given the above (and the fact that cloud-init doesn't run for another ~5s after these lines), I _think_ this is a systemd/kernel interface issue, not a cloud-init issue. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1902960 Title: Upgrade from 245.4-4ubuntu3.3 to 245.4-4ubuntu3.2 appears to break DNS resolution in some cases Status in cloud-init package in Ubuntu: New Status in systemd package in Ubuntu: Invalid Bug description: The systemd upgrade 245.4-4ubuntu3.3 to 245.4-4ubuntu3.2 appears to have broken DNS resolution across much of our Azure fleet earlier today. We ended up mitigating this by forcing reboots on the associated instances, no combination of networkctl reload, reconfigure, systemctl daemon-reexec, systemctl daemon-reload, netplan generate, netplan apply would get resolvectl to have a DNS server again. The main symptom appears to have been systemd-networkd believing it wasn't managing the eth0 interfaces: ubuntu@machine-1:~$ sudo networkctl IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback carrier unmanaged 2 eth0 ether routable unmanaged 2 links listed. Which eventually made them lose their DNS resolvers: ubuntu@machine-1:~$ sudo resolvectl dns Global: Link 2 (eth0): After rebooting, we see this behaving properly: ubuntu@machine-1:~$ sudo networkctl list IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback carrier unmanaged 2 eth0 ether routable configured 2 links listed. ubuntu@machine-1:~$ sudo resolvectl dns Global: Link 2 (eth0): 168.63.129.16 This appears to be specifically linked to the upgrade, i.e. we were able to provoke the issue by upgrading the systemd package, so I suspect it's part of the packaging in the upgrade process. --- ProblemType: Bug ApportVersion: 2.20.11-0ubuntu27.10 Architecture: amd64 CasperMD5CheckResult: skip DistroRelease: Ubuntu 20.04 Lspci-vt: -[0000:00]-+-00.0 Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (AGP disabled) +-07.0 Intel Corporation 82371AB/EB/MB PIIX4 ISA +-07.1 Intel Corporation 82371AB/EB/MB PIIX4 IDE +-07.3 Intel Corporation 82371AB/EB/MB PIIX4 ACPI \-08.0 Microsoft Corporation Hyper-V virtual VGA Lsusb: Error: command ['lsusb'] failed with exit code 1: Lsusb-t: Lsusb-v: Error: command ['lsusb', '-v'] failed with exit code 1: MachineType: Microsoft Corporation Virtual Machine Package: systemd 245.4-4ubuntu3.3 PackageArchitecture: amd64 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=C.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-1031-azure root=PARTUUID=2e08bba3-68b4-4a16-af3b-47b73bd138a9 ro console=tty1 console=ttyS0 earlyprintk=ttyS0 panic=-1 ProcVersionSignature: Ubuntu 5.4.0-1031.32-azure 5.4.65 Tags: focal uec-images Uname: Linux 5.4.0-1031-azure x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: N/A _MarkForUpload: True dmi.bios.date: 12/07/2018 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 090008 dmi.board.name: Virtual Machine dmi.board.vendor: Microsoft Corporation dmi.board.version: 7.0 dmi.chassis.asset.tag: 7783-7084-3265-9085-8269-3286-77 dmi.chassis.type: 3 dmi.chassis.vendor: Microsoft Corporation dmi.chassis.version: 7.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr090008:bd12/07/2018:svnMicrosoftCorporation:pnVirtualMachine:pvr7.0:rvnMicrosoftCorporation:rnVirtualMachine:rvr7.0:cvnMicrosoftCorporation:ct3:cvr7.0: dmi.product.name: Virtual Machine dmi.product.uuid: 4412ad79-83fa-f845-b7c2-6f30dd4f1950 dmi.product.version: 7.0 dmi.sys.vendor: Microsoft Corporation To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1902960/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
