Public bug reported: Using the cloud-image of resolute 26.04.1 (https://cloud- images.ubuntu.com/resolute/current/resolute-server-cloudimg-amd64.ova 2026-09-27) I find that I'm unable to use the XCPng live migration feature to move a VM from one host to the other. I do the migration and it seems to work, but a few minutes after the migration is finished the guest gets kernel task hangs most of the time and I see a hung task message in the console. This causes future login processes to hang and ssh doesn't let me in. I get the same behavior on the console.
I currently believe that this happens most of the time of the affected version. I did manage to get it to happen and have journalctl record the interaction. (see attachment guest-hang-kernel-log.txt) I have tested some other distributions: cloud version of noble - not present Linux ubuntu-noble-24 6.8.0-147-generic #147-Ubuntu SMP PREEMPT_DYNAMIC Thu Sep 24 11:33:16 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux cloud version of questing - not present Linux test-questing 6.17.0-41-generic #41-Ubuntu SMP PREEMPT_DYNAMIC Sat Jun 20 18:01:40 UTC 2026 x86_64 GNU/Linux cloud version of resolute - present Linux ubuntu-resolute-26 7.0.0-38-generic #38-Ubuntu SMP PREEMPT_DYNAMIC Fri Sep 4 09:10:14 UTC 2026 x86_64 GNU/Linux cloud version of stonking - not present Linux test-stonking 7.3.0-9-generic #9-Ubuntu SMP PREEMPT_DYNAMIC Mon Oct 5 10:38:02 UTC 2026 x86_64 GNU/Linux iso server installation of resolute - not present Linux test-resolute-iso-26 7.0.0-38-generic #38-Ubuntu SMP PREEMPT_DYNAMIC Fri Sep 4 09:10:14 UTC 2026 x86_64 GNU/Linux I'm at a bit of a loss as to where to go from here debugging wise. I don't see different kernels, both images use the -generic kernels. I also asked the guys in the xcpng fourum: https://xcp- ng.org/forum/topic/12531/problem-migrating-ubuntu-guest-kernel-hung- tasks/ ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-38-generic 7.0.0-38.38 ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14 Uname: Linux 7.0.0-38-generic x86_64 AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Oct 16 13:38 seq crw-rw---- 1 root audio 116, 33 Oct 16 13:38 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: N/A CasperMD5CheckResult: unknown CloudBuildName: server CloudSerial: 20260927 Date: Fri Oct 16 13:42:06 2026 Lsusb: Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd QEMU Tablet Lsusb-t: /: Bus 001.Port 001: Dev 001, Class=root_hub, Driver=uhci_hcd/2p, 12M |__ Port 002: Dev 002, If 0, Class=Human Interface Device, Driver=usbhid, 12M MachineType: Xen HVM domU PciMultimedia: ProcEnviron: LANG=C.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-color ProcFB: 0 cirrus-qemudrmf ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-38-generic root=UUID=747687d9-c20c-41f8-bfb8-7f4a57910c51 ro console=tty1 console=ttyS0 RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 10/06/2026 dmi.bios.release: 4.17 dmi.bios.vendor: Xen dmi.bios.version: 4.17 dmi.chassis.type: 1 dmi.chassis.vendor: Xen dmi.modalias: dmi:bvnXen:bvr4.17:bd10/06/2026:br4.17:svnXen:pnHVMdomU:pvr4.17:cvnXen:ct1:cvr:sku:pfa: dmi.product.name: HVM domU dmi.product.version: 4.17 dmi.sys.vendor: Xen ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug cloud-image resolute ** Attachment added: "kernel log from a boot where the issue presented." https://bugs.launchpad.net/bugs/2171183/+attachment/6009896/+files/guest-hang-kernel-log.txt ** Description changed: Using the cloud-image of resolute 26.04.1 (https://cloud- images.ubuntu.com/resolute/current/resolute-server-cloudimg-amd64.ova 2026-09-27) I find that I'm unable to use the XCPng live migration feature to move a VM from one host to the other. I do the migration and it seems to work, but a few minutes after the migration is finished the guest gets kernel task hangs most of the time and I see a hung task message in the console. This causes future login processes to hang and ssh doesn't let me in. I get the same behavior on the console. I currently believe that this happens most of the time of the affected version. I did manage to get it to happen and have journalctl record the interaction. (see attachment guest-hang-kernel-log.txt) I have tested some other distributions: cloud version of noble - not present Linux ubuntu-noble-24 6.8.0-147-generic #147-Ubuntu SMP PREEMPT_DYNAMIC Thu Sep 24 11:33:16 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux cloud version of questing - not present Linux test-questing 6.17.0-41-generic #41-Ubuntu SMP PREEMPT_DYNAMIC Sat Jun 20 18:01:40 UTC 2026 x86_64 GNU/Linux cloud version of resolute - present Linux ubuntu-resolute-26 7.0.0-38-generic #38-Ubuntu SMP PREEMPT_DYNAMIC Fri Sep 4 09:10:14 UTC 2026 x86_64 GNU/Linux cloud version of stonking - not present Linux test-stonking 7.3.0-9-generic #9-Ubuntu SMP PREEMPT_DYNAMIC Mon Oct 5 10:38:02 UTC 2026 x86_64 GNU/Linux iso server installation of resolute - not present Linux test-resolute-iso-26 7.0.0-38-generic #38-Ubuntu SMP PREEMPT_DYNAMIC Fri Sep 4 09:10:14 UTC 2026 x86_64 GNU/Linux + I'm at a bit of a loss as to where to go from here debugging wise. I + don't see different kernels, both images use the -generic kernels. - I'm at a bit of a loss as to where to go from here debugging wise. I don't see different kernels, both images use the -generic kernels. + I also asked the guys in the xcpng fourum: https://xcp- + ng.org/forum/topic/12531/problem-migrating-ubuntu-guest-kernel-hung- + tasks/ ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-38-generic 7.0.0-38.38 ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14 Uname: Linux 7.0.0-38-generic x86_64 AlsaDevices: - total 0 - crw-rw---- 1 root audio 116, 1 Oct 16 13:38 seq - crw-rw---- 1 root audio 116, 33 Oct 16 13:38 timer + total 0 + crw-rw---- 1 root audio 116, 1 Oct 16 13:38 seq + crw-rw---- 1 root audio 116, 33 Oct 16 13:38 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: N/A CasperMD5CheckResult: unknown CloudBuildName: server CloudSerial: 20260927 Date: Fri Oct 16 13:42:06 2026 Lsusb: - Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub - Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd QEMU Tablet + Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub + Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd QEMU Tablet Lsusb-t: - /: Bus 001.Port 001: Dev 001, Class=root_hub, Driver=uhci_hcd/2p, 12M - |__ Port 002: Dev 002, If 0, Class=Human Interface Device, Driver=usbhid, 12M + /: Bus 001.Port 001: Dev 001, Class=root_hub, Driver=uhci_hcd/2p, 12M + |__ Port 002: Dev 002, If 0, Class=Human Interface Device, Driver=usbhid, 12M MachineType: Xen HVM domU PciMultimedia: - + ProcEnviron: - LANG=C.UTF-8 - PATH=(custom, no user) - SHELL=/bin/bash - TERM=xterm-color + LANG=C.UTF-8 + PATH=(custom, no user) + SHELL=/bin/bash + TERM=xterm-color ProcFB: 0 cirrus-qemudrmf ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-38-generic root=UUID=747687d9-c20c-41f8-bfb8-7f4a57910c51 ro console=tty1 console=ttyS0 RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 10/06/2026 dmi.bios.release: 4.17 dmi.bios.vendor: Xen dmi.bios.version: 4.17 dmi.chassis.type: 1 dmi.chassis.vendor: Xen dmi.modalias: dmi:bvnXen:bvr4.17:bd10/06/2026:br4.17:svnXen:pnHVMdomU:pvr4.17:cvnXen:ct1:cvr:sku:pfa: dmi.product.name: HVM domU dmi.product.version: 4.17 dmi.sys.vendor: Xen -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2171183 Title: kernel task hang after live migration of xcpng guest of cloud-image resolute To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2171183/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
