This page may be of help I would run it on sda6 first see if it works.
Ubuntu Handbook
Other alternative would be to use the live Dvd/usb to copy all important files to a seperate external source or use the backup utility to do that. and do a complete reinstall.
Good Luck.
Well it is a same old story - how do you "backup" data from different application?
I will not post a list of them...
So far my "solution" is to have "important files " on RAID and just manually copy entire folders, almost daily.
And again , as in this case - how do you backup entire OS so when it bombs like this one did you do not loose an array of packages ?
I just build a simple HF circuit in EAGLE / spice and it is gone....
Of course partially because Windowze / Wine puts stuff in drives and Linux wants it in folders.
Perhaps another post after I get this resolved.
PS
I did check the link.
I am not sure if mounting the faulty sda6 is the problem.
And I did do several update-grub and it did not change a thing.
Perhaps I am overanalysing the problem and should just try as the link did -
I got nothing to loose.
ADDENDUM
Here is my LAST update-grub mainly posted for those who (desperately) NEED to know EXACT
number of Linux image file.
I should see all /dev/x in grub menu , with an execptiuon of the last installed - sda25
grub found all including "25" but sda6 cannot connect with it.
qe@qe-desktop:~$ sudo update-grub
[sudo] password for qe:
Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/init-select.cfg'
/usr/bin/grub-editenv: error: invalid environment block.
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.11.0-25-generic
Found initrd image: /boot/initrd.img-5.11.0-25-generic
Found linux image: /boot/vmlinuz-5.11.0-22-generic
Found initrd image: /boot/initrd.img-5.11.0-22-generic
Found linux image: /boot/vmlinuz-5.11.0-17-generic
Found initrd image: /boot/initrd.img-5.11.0-17-generic
Found Ubuntu 21.04 (21.04) on /dev/sda25
Found Ubuntu 21.04 (21.04) on /dev/sda3
Found Ubuntu 21.04 (21.04) on /dev/sda6
Found Ubuntu 21.04 (21.04) on /dev/sdb2
Found Ubuntu 20.10 (20.10) on /dev/sdb20
Found Ubuntu 21.04 (21.04) on /dev/sdb22
Found Ubuntu 21.04 (21.04) on /dev/sdb24
Found Ubuntu 21.04 (21.04) on /dev/sdc31
Found Ubuntu 21.04 (21.04) on /dev/sdc32
Found Ubuntu 21.04 (21.04) on /dev/sdc6
Adding boot menu entry for UEFI Firmware Settings
done
qe@qe-desktop:~$
So I rebooted and expected to see all OS in grub menu .
No so , only dev/sdax, and grub run sda25 - as default , as expected .
The question is - why update-grub finds ALL Ubuntu OS
on ALL HDD and grub menus does not show all?
Could this be a problem indicator ?
/usr/bin/grub-editenv: error: invalid environment block.
Can that file be edited ? (let me try )
No silly - its binary file