error: attempt to read or write outside of disk 'hd0'
(the cause for this below is wrong)
I started using an external hdd to backup using the built in backup software (I'm guessing the back end of this is deja-dup).
After this I start getting
error: attempt to read or write outside of disk 'hd0' on boot.
I can still boot since the OS itself is in another drive and the error screen offers to press enter to continue.
It is a minor bug but nice to fix. Does anyone have a workaround?
The reason mentioned in the original question is not correct. It probably had to do with an update on grub (I honestly don't know).
Eventually the error caused me to not be able to boot and redirected to grub command line (grub rescue).
I tried this fix but was unsuccessful. Trying to read/write under
(hd0,mdsosX) throws the
error: attempt to read or write etc.. still.
My fix is below in the answer.
xxx@xxxx:~$ uname -a
Linux xxxx 4.8.0-58-generic #63~16.04.1-Ubuntu SMP Mon Jun 26 18:08:51 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux