Hello I've encountered a problem on a server where /boot is on a RAID partition on sda and sdb, grub is installed to sda and sdb, but upgrading sdc causes a hang after:
GRUB loading. Welcome to GRUB! and yet leaving the drive bay for sdc empty, it boots as normal. I'm most interested in the general question: *how* can the GRUB core be loaded and run by the MBR without it either showing the menu or a prompt? My understanding is that the core will try to find the prefix and read within that grub.cfg and if any stage fails it will show a grub rescue> or grub> prompt. So the only possibilities I can think of are: a) the core that's being loaded is corrupt (and presumably not from where it's recently been installed) b) there's a mismatch between boot.img and a core (one of which is outdated), perhaps setting wrong environment variables or disk geometry c) some disk function, perhaps in the BIOS, is hanging (in this case the sdc light is lit) Full details of my case (plus a debug method I intend to use on the server and some minor bugs) are at: https://serverfault.com/questions/869559/grub-hangs-before-menu-after-a-raid-upgrade-how-to-debug Some other cases under different conditions but with failure at the same point: * https://forums.freenas.org/index.php?threads/stuck-at-welcome-to-grub.54860/ * https://forum.openmediavault.org/index.php/Thread/7389-Installed-latest-ISO-now-stuck-at-Welcome-to-GRUB/ * https://serverfault.com/questions/241109/linux-software-raid1-how-to-boot-after-physically-removing-dev-sda-lvm-md * https://forum.manjaro.org/t/usb-boot-grub-freezes/21350 * https://bugzilla.redhat.com/show_bug.cgi?id=805747 and a couple of unanswered questions on this list: * http://lists.gnu.org/archive/html/help-grub/2013-07/msg00054.html * http://lists.gnu.org/archive/html/help-grub/2011-03/msg00034.html These tend to be a few years old, so I'm wondering if upgrading from 1.99 to 2.02 will fix a bug. I could read hundreds of source files, but would prefer a few words of explanation... Thanks. CK _______________________________________________ Help-grub mailing list Help-grub@gnu.org https://lists.gnu.org/mailman/listinfo/help-grub
