What does this error mean ?
/dev/mapper/ubuntu--vg-root: clean
It was shown during startup but the system booted fine.
Do I have to do anything?
What does this error mean ?
/dev/mapper/ubuntu--vg-root: clean
It was shown during startup but the system booted fine.
Do I have to do anything?
No, it's not an error. It just means that your filesystem has been marked "clean", meaning no issues.
No issues at all with that message, in fact it's good to see it.