For Azure users (the same should work in any cloud, with small changes) that end up here while looking for this bug, the steps to recover are:
Deploy a recovery VM using AzCli or just attach a copy of the affected OS vm disk to a rescue VM. Once done, connected to rescue VM and: $ sudo su - # mkdir /rescue # mount /dev/sdc1 /rescue # for fs in {proc,sys,tmp,dev}; do mount -o bind /$fs /rescue/$fs; done # cd /rescue # chroot /rescue # lsblk <-- this will identify the attached disk, usualy /dev/sdc # grub-install /dev/sdc # exit # cd / # for fs in {proc,sys,tmp,dev}; do umount /rescue/$fs; done # umount /rescue Now you should be able to swap back the repaired disk to affected VM. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1889509 Title: grub boot error : "symbol 'grub_calloc' not found To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1889509/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs