I believe it’s a configuration issue: If we use the default Ubuntu kernel as the ”dump capture kernel“[1], we need to reserve more memory – the default 128MB, generated by the linux- crashdump post-install script, is not enough, causing a -ENOMEM failure/BUG in a function of tree_plugin.h.
This issue even exists in the native case for Ubuntu 14.10. And essentially, Ubuntu 14.04 has the same issue, but probably the kernel/initramfs of 14.04 aren’t so big that the early kernel panic at “kernel BUG at /build/buildd/linux-3.16.0/kernel/rcu/tree_plugin.h:2332” doesn’t happen – however, at a later stage of 14.04 boot-up, many Out-of-Memory warnings are printed in my tests, though the crashdump can be created. If I change the size of the default memory reserved for kdump from 128MB to 256MB, the issue won’t appear. How to change the size[2] – please update the grub.conf and change the kernel parameter [3] crashkernel=384M-:128M to crashkernel=384M-:256M. References: [1] https://wiki.archlinux.org/index.php/Kdump [2] http://docs.oracle.com/cd/E19140-01/html/821-0281/gkvnc.html [3] The syntax of the kernel parameter crashkernel: https://www.kernel.org/doc/Documentation/kernel-parameters.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1359980 Title: [Hyper-V] Unable to perform a full kernel crash on Ubuntu 14.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1359980/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
