(The zero size problem mentioned above also occurs occasionally on ubuntu 18.04, and the workaround is to add a sleep in the user script after modprobe nbd, so that's really a separate problem.)
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1896350 Title: nbd locks system? Status in linux package in Ubuntu: Confirmed Bug description: I'm trying to use nbd on ubuntu 20.04 like so: qemu-img create -f qcow2 foo.img 500M sudo modprobe nbd sudo qemu-nbd --disconnect /dev/nbd15 || true sudo qemu-nbd --connect=/dev/nbd15 --cache=writeback --format=qcow2 foo.img sudo mkfs.ext4 -L root -O "^64bit" -E nodiscard /dev/nbd15 sudo qemu-nbd --disconnect /dev/nbd15 It seems to work on some systems, but even on those systems, strange things show up in syslog, e.g. Sep 19 15:46:02 thinky kernel: [27042.757768] block nbd15: Possible stuck request 00000000dd2d7f93: control (read@135168,126976B). Runtime 450 seconds Sep 19 15:46:26 thinky kernel: [27067.333867] INFO: task systemd-udevd:17364 blocked for more than 241 seconds. and in kern.log, e.g. ... Sep 19 16:17:27 thinky kernel: [ 71.676026] Buffer I/O error on dev nbd15, logical block 7, async page read Sep 19 16:17:27 thinky kernel: [ 71.676049] blk_update_request: I/O error, dev nbd15, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Sep 19 16:17:27 thinky kernel: [ 71.676051] Buffer I/O error on dev nbd15, logical block 0, async page read Sep 19 16:17:27 thinky kernel: [ 71.676061] blk_update_request: I/O error, dev nbd15, sector 1 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Sep 19 16:17:27 thinky kernel: [ 71.676063] Buffer I/O error on dev nbd15, logical block 1, async page read Sep 19 16:17:27 thinky kernel: [ 71.676147] ldm_validate_partition_table(): Disk read failed. Sep 19 16:17:27 thinky kernel: [ 71.676324] Dev nbd15: unable to read RDB block 0 Sep 19 16:17:27 thinky kernel: [ 71.676473] nbd15: unable to read partition table Sep 19 16:17:27 thinky kernel: [ 71.678340] nbd15: detected capacity change from 0 to 524288000 Sep 19 16:17:27 thinky kernel: [ 71.678536] ldm_validate_partition_table(): Disk read failed. Sep 19 16:17:27 thinky kernel: [ 71.678719] Dev nbd15: unable to read RDB block 0 Sep 19 16:17:27 thinky kernel: [ 71.678947] nbd15: unable to read partition table Sep 19 16:17:27 thinky kernel: [ 71.679985] ldm_validate_partition_table(): Disk read failed. Sep 19 16:17:27 thinky kernel: [ 71.680172] Dev nbd15: unable to read RDB block 0 Sep 19 16:17:27 thinky kernel: [ 71.680366] nbd15: unable to read partition table Sep 19 16:17:27 thinky kernel: [ 71.680647] block nbd15: Attempted send on invalid socket and the system seems to hang on reboot. Also, on another system (an up to date mac, running ubuntu 20.04 in virtualbox), the mkfs.ext4 fails, complaining the device is zero size. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-47-generic 5.4.0-47.51 ProcVersionSignature: Ubuntu 5.4.0-47.51-generic 5.4.55 Uname: Linux 5.4.0-47-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu27.6 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: dank 2948 F.... pulseaudio /dev/snd/controlC2: dank 2948 F.... pulseaudio /dev/snd/controlC0: dank 2948 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Sat Sep 19 16:28:43 2020 HibernationDevice: RESUME=UUID=7aecd5d3-2f5b-4c07-8867-801e63868a0f InstallationDate: Installed on 2017-04-29 (1239 days ago) InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412) MachineType: LENOVO ThinkServer TS140 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-47-generic root=UUID=ff9a24e4-277d-4baf-819b-826a33d5bb5e ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-5.4.0-47-generic N/A linux-backports-modules-5.4.0-47-generic N/A linux-firmware 1.187.2 RfKill: SourcePackage: linux UpgradeStatus: Upgraded to focal on 2020-05-01 (141 days ago) dmi.bios.date: 09/19/2014 dmi.bios.vendor: LENOVO dmi.bios.version: FBKT99AUS dmi.board.name: ThinkServer TS140 dmi.board.vendor: LENOVO dmi.board.version: Not Defined dmi.chassis.type: 7 dmi.chassis.vendor: LENOVO dmi.chassis.version: To Be Filled By O.E.M. dmi.modalias: dmi:bvnLENOVO:bvrFBKT99AUS:bd09/19/2014:svnLENOVO:pnThinkServerTS140:pvr70A4000HUX:rvnLENOVO:rnThinkServerTS140:rvrNotDefined:cvnLENOVO:ct7:cvrToBeFilledByO.E.M.: dmi.product.family: To be filled by O.E.M. dmi.product.name: ThinkServer TS140 dmi.product.sku: LENOVO_PN_ThinkServer TS140 dmi.product.version: 70A4000HUX dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1896350/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
