VERIFICATION ON FOCAL Installed makedumpfile from proposed. Testing on a Focal machine running 5.11 kernel.
# uname -rv 5.11.0-40-generic #44~20.04.1-Ubuntu SMP Wed Oct 20 19:04:34 UTC 2021 Trigger crash: # echo 1 > /proc/sys/kernel/sysrq # echo c > /proc/sysrq-trigger >From console output : [ 57.418037] kdump-tools[548]: Starting kdump-tools: [ 57.419099] kdump-tools[554]: * running makedumpfile -c -d 31 /proc/vmcore /var/crash/202110271414/dump-incomplete Copying data : [100.0 %] / eta: 0s [ 61.481957] kdump-tools[572]: The kernel version is not supported. [ 61.494134] kdump-tools[572]: The makedumpfile operation may be incomplete. [ 61.501242] kdump-tools[572]: The dumpfile is saved to /var/crash/202110271414/dump-incomplete. [ 61.502711] kdump-tools[572]: makedumpfile Completed. [ 61.503885] kdump-tools[554]: * kdump-tools: saved vmcore in /var/crash/202110271414 [ 61.851266] kdump-tools[554]: * running makedumpfile --dump-dmesg /proc/vmcore /var/crash/202110271414/dmesg.202110271414 [ 61.867626] kdump-tools[576]: The kernel version is not supported. [ 61.871305] kdump-tools[576]: The makedumpfile operation may be incomplete. [ 61.877902] kdump-tools[576]: The dmesg log is saved to /var/crash/202110271414/dmesg.202110271414. [ 61.881797] kdump-tools[576]: makedumpfile Completed. [ 61.885645] kdump-tools[554]: * kdump-tools: saved dmesg content in /var/crash/202110271414 [ 61.989595] kdump-tools[579]: Wed, 27 Oct 2021 14:14:21 +0000 [ 62.123243] kdump-tools[580]: Rebooting. [ 62.561341] reboot: Restarting system Makedumpfile compress the dump and does not fall back to cp. ** Tags removed: verification-needed verification-needed-focal ** Tags added: verification-done verification-done-focal -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to makedumpfile in Ubuntu. https://bugs.launchpad.net/bugs/1942784 Title: makedumpfile falls back to cp on focal with 5.11 kernel Status in makedumpfile package in Ubuntu: Fix Released Status in makedumpfile source package in Focal: Fix Committed Bug description: [IMPACT] When running Focal with the hwe 5.11 kernel makedumpfile is not working as it should. Instead of compressing the dump makedumpfile falls back to cp. This can create problems on systems with very large RAM and result into exhausting all storage on the host. [FIX] This can be resolved with upstream commit f1197543d1c4 ([PATCH] Retrieve MAX_PHYSMEM_BITS from vmcoreinfo). The reason for falling back to cp is that without this patch makedumpfile calculates wrongly the memory layout. This happens after the kernel commit 1d50e5d0c505 ("crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS'to vmcoreinfo"). With this commit applied, reading MAX_PHYSMEM_BITS from vmcoreinfo instead of inferring lead to correctly detecting the memory layout and creating the dump file properly. [TEST CASE] For testing a machine running focal with the 5.11 kernel is required. Then trigger a crash. On the console we can see that makedumpfile fails and `falls back to cp`. In /var/crash we can see that no dmesg file is created and instead of the dump file the uncompressed vmcoreinfo is created. [WHERE PROBLEMS COULD OCCUR] Any regression potential would involve the crash dump not being created after a crash in case kdump is configured. [OTHER] Only Focal with 5.11 kernel is affected. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/makedumpfile/+bug/1942784/+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
