I have booted from a live USB ("Try Ubuntu"), that also has a persistent option set (I used LiLi to create one) to do some tests for this pcie hotplug issue I'm having.
I'm trying to test some boot paramaters (like in this question) by doing this
sudo nano /etc/default/grub sudo update-grub
The problem is that that last command gives me this:
/usr/sbin/grub-probe: error: failed to get canonical path of /cow.
It looks like
/cow is the file-system that is mounted on
/, according to:
:~# df Filesystem 1K-blocks Used Available Use% Mounted on /cow 4056896 2840204 1007284 74% / udev 1525912 4 1525908 1% /dev tmpfs 613768 844 612924 1% /run ....
Is there a way for me to run update-grub?
You'll need to do a bit of remounting and remapping.
After booting the liveCD, we'll mount the Ubuntu partition to
/dev/sd*#is updated to your Ubuntu partition.
If you have a separate
/bootpartition, we'll need to mount it in
/dev/sd*#is updated to your
This should mount it with enough access to get the canonical path if needed, but we'll likely not need this.
To finish up, just update grub with the correct root and target:
/dev/sdXis the disk(not the partition) where we want GRUB.