Ah, okay, that's an issue. Not only do we not have an easy way of measuring how much memory a kernel needs to boot, we don't know how that requirement varies depending on the system configuration...
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to kexec-tools in Ubuntu. https://bugs.launchpad.net/bugs/785394 Title: Hard-coded crashkernel=... memory reservation in /etc/grub.d/10_linux is insufficient Status in “grub” package in Ubuntu: Fix Released Status in “kexec-tools” package in Ubuntu: Fix Released Status in “grub” source package in Precise: In Progress Status in “grub” source package in Quantal: In Progress Status in “grub” source package in Raring: In Progress Status in “grub” source package in Saucy: In Progress Bug description: Binary package hint: grub-pc This concerns grub-pc 1.99~rc1-13ubuntu3 in Ubuntu Natty. The /etc/grub.d/10_linux file contains this snippet: # add crashkernel option if we have the required tools if [ -x "/usr/bin/makedumpfile" ] && [ -x "/sbin/kexec" ]; then GRUB_CMDLINE_EXTRA="$GRUB_CMDLINE_EXTRA crashkernel=384M-2G:64M,2G-:128M" fi I am on a system with 2GB of RAM (reported as 2038MB), and according to the kernel startup messages, 64MB is reserved for the crash kernel. Unfortunately, this does not appear to be enough memory for the regular Ubuntu kernel to boot. I am attaching a kernel log obtained via serial cable; it shows the initial boot, a crash in the kernel's video-driver-related code, the subsequent crashkernel boot, and then an apparent "out of memory" kernel panic. (A side effect of the "double crash" is that the system is left unresponsive, requiring a manual reset instead of rebooting itself automatically.) If I double the memory numbers in the crashkernel=... argument, so that the reservation is 128MB, the system correctly goes on to attempt a vmcore dump and reboot. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub/+bug/785394/+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
