[Bug 1889509] Re: grub boot error : "symbol 'grub_calloc' not found

[Julian Andres Klode]

No certainly not. The issue here is if you have the wrong device
configured to install grub on, it fails to install to it, but does not
fail the upgrade process, and the disks grub loader does not match the
grub on the boot partition.

Or you converted to raid1 manually or copied your disk and did not
reconfigure grub.

Running dpkg-reconfigure grub-pc should likely fix it, as it will ask
you for the devices to install on again.

This is not a problem on UEFI systems fwiw, as they do not use a small
image in MBR and load the rest from /boot, but a single monolithic grub
image in the ESP.

Some more work is being done to harden this.

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https://bugs.launchpad.net/bugs/1889509

Title:
  grub boot error : "symbol 'grub_calloc' not found

Status in grub2 package in Ubuntu:
  Confirmed
Status in grub2 package in Debian:
  New

Bug description:
  After updating grub2 (to 2.02~beta2-36ubuntu3.26) and rebooting, my
  server does not boot:

  Booting from Hard Disk 0...
  error: symbol `grub_calloc' not found.
  Entering rescue mode...
  grub rescue> _

  I rebooted 3 servers in this way (all running Ubuntu 16.04.6 LTS) and
  all hung.

  A lot of other people are reporting the same problem at:

  https://askubuntu.com/questions/1263125/how-to-fix-a-grub-boot-error-symbol-grub-calloc-not-
  found.

  ---

  Above most likely means that dpkg debconf no longer knows about the
  correct drives to install grub onto.

  Please boot & mount all the target disks and execute

  $ sudo dpkg-reconfigure grub-pc

  You will be asked which drives to install grub onto, and then grub
  will be installed onto them, and more importantly, it will remember
  where to install grub to, on all future upgrades.

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