rescue boot cannot check root fs

[Ralf Mardorf]

Hi,

if init is systemd as it is for Ubuntu, you could add the kernel
parameter fsck.mode=force and fsck.repair=[option] to force a check of
ext4 or all file systems. I don't know if it's limited to ext4 or does
check all file systems or you could use
https://manpages.ubuntu.com/manpages/xenial/man8/systemd-fsck-root.service.8.html
. I would do neither one or the other.

I recommend to boot an Ubuntu live ISO from a DVD or an USB stick and to
run fsck manually by command line, because this way you don't need to
learn how to add the kernel parameter, what a force does or doesn't
check or else you don't need to learn how to use this systemd thingy,
instead you can simple use fsck by command line and you can use it
really interactively, e.g. if you need to repair something, just launch
a browser and read how to do it, assuming you need this kind of help. A
live media is a full Ubuntu flavour install, with e.g. a browser and
command line to run fsck, let alone that the root file system you want
to check isn't mounted by default.

Regards,
Ralf