Wondering how to resolve Error symbol grub_calloc not found ? Our server management services team is here to lend a hand with your queries and issues.

How to resolve Error symbol grub_calloc not found ?

This error message points to a generic problem where the bootloader code itself is not compatible with the bootloader modules, hence the symbol error.

Typical error looks as shown below:

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

Today, let us see the steps followed by our support techs to resolve it.

• Firstly, you have to detach /dev/sda1 volume from the ec2 instance.
• Then, Mount it on another server (probably start a new temp rescue server with the same operating system)
• Login in to the rescue server and run the below

$ 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

• Then, Detach fixed volume from rescue server
• Finally, Attach it back to the original server (as /dev/sda1)  and Done

Conclusion

To wrap up, our Support Engineers demonstrated a quick fix for resolving the error symbol grub_calloc. We also learned about the root cause behind this specific error.