Craig: > The lockup is a little different now. Whereas previously the system would > hang before any of the snapshots were removed, now some of the snapshots are > successfully umount'd and lvremove'd before the hang. This could be the > result of changes made to the script that does the umount and lvremove, > reordering the sequence of the snapshots, which consist of home, root, and > var partitions.
That is a red herring. I had done the umounting/removing alternating until this issue appeared to me. I first assumed that lvremove caused the hangs but after dividing the script into a split phase operation (unmount all first, lvremove all as second) the issue appeared always during the unmount step. But maybe i have found a workaround: Instead of running the script in context of bacula-fd, i use "at" to decouple the unmount/lvremove step from bacula-fd and delay it for about two minutes. I had freezes at maybe two out of three backup jobs before and no one during the last three backup jobs after implementing this change. I guess the issue lies somewhere in the way kernel, bacula-fd, bash and unmount interact together. Breaking up this chain by running the unmount/lvremove part outside bacula-fd and after the backup job itself has been finished circumvents the issue to appear. -- 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/1115753 Title: Umount of Multiple LVM Snapshots Causes 'soft lockup CPU#0 stuck for' Status in “linux” package in Ubuntu: Incomplete Bug description: Simultaneous umount of multiple lvm snapshots causes system to hang / freeze / deadlock. Window manager freezes. If umount is executed in a non window-manager tty, messages containing "BUG", "blocked for more than xx seconds", and a list of tasks associated with each of the 8 cpu cores will scroll up at regular intervals. The tasks assigned to each cpu core are unchanging over time, appearing to be deadlocked. No relevant information is left in system logs. Hard reset / poweroff is required. Problem does not occur 100% of the time. It is less likely to occur if umount is done shortly after mount. Problem still occurs -- but less frequently -- if lazy umount -l is used. Snapshots are read-only, and are mounted read-only. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: linux-image-3.2.0-37-generic 3.2.0-37.58 ProcVersionSignature: Ubuntu 3.2.0-37.58-generic 3.2.35 Uname: Linux 3.2.0-37-generic x86_64 AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24. ApportVersion: 2.0.1-0ubuntu17.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: craig 3257 F.... pulseaudio /dev/snd/controlC0: craig 3257 F.... pulseaudio CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found. Card0.Amixer.info: Card hw:0 'SB'/'HDA ATI SB at 0xfeb00000 irq 16' Mixer name : 'Realtek ALC889' Components : 'HDA:10ec0889,1043846b,00100004' Controls : 49 Simple ctrls : 24 Card1.Amixer.info: Card hw:1 'HDMI'/'HDA ATI HDMI at 0xfea30000 irq 98' Mixer name : 'ATI R6xx HDMI' Components : 'HDA:1002aa01,00aa0100,00100100' Controls : 6 Simple ctrls : 1 Card1.Amixer.values: Simple mixer control 'IEC958',0 Capabilities: pswitch pswitch-joined penum Playback channels: Mono Mono: Playback [on] Date: Mon Feb 4 18:58:37 2013 HibernationDevice: RESUME=UUID=b788f786-ba76-4eb0-991f-d3bbc339d3f7 InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111011) IwConfig: lo no wireless extensions. eth0 no wireless extensions. MachineType: To be filled by O.E.M. To be filled by O.E.M. MarkForUpload: True ProcEnviron: TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.2.0-37-generic root=/dev/mapper/volgroup0-root ro RelatedPackageVersions: linux-restricted-modules-3.2.0-37-generic N/A linux-backports-modules-3.2.0-37-generic N/A linux-firmware 1.79.1 RfKill: SourcePackage: linux UpgradeStatus: Upgraded to precise on 2012-10-23 (104 days ago) dmi.bios.date: 09/27/2011 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 0813 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: Crosshair V Formula dmi.board.vendor: ASUSTeK Computer INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: To Be Filled By O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: To Be Filled By O.E.M. dmi.chassis.version: To Be Filled By O.E.M. dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0813:bd09/27/2011:svnTobefilledbyO.E.M.:pnTobefilledbyO.E.M.:pvrTobefilledbyO.E.M.:rvnASUSTeKComputerINC.:rnCrosshairVFormula:rvrRev1.xx:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.: dmi.product.name: To be filled by O.E.M. dmi.product.version: To be filled by O.E.M. dmi.sys.vendor: To be filled by O.E.M. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1115753/+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
