[Ubuntu-users] fsck shows errors on main partition only when mounted

[K. Frank]

Hello All -

I have just installed ubuntu on a former windows machine whose
os had become corrupted, and fsck reports disk errors.

Should I care, and how can I fix this?

I run:

   sudo fsck -n /dev/sda1

on my main partition, and it reports errors, ending with:

   WARNING: Filesystem still has errors

(Errors reported include "corrupted orphan linked listed found."
and "Free blocks count wrong" among others.")

The partition is mounted, as it's my main partition with ubuntu
(and fsck) on it.

With a mind to fix the errors, I boot off of an ubuntu-installation
flash drive, and run ubuntu from there without mounting my
hard drive.  Now running fsck from the flash drive shows no
errors.

Then, running off the flash drive, I deleted the partitions on
the hard drive, repartitioned, and reformatted (as ext4), and
reinstalled ubuntu.

But I see the same problem -- no errors when running fsck
from the flash drive with the hard drive not mounted, but
errors when running from the hard drive with the hard drive
mounted.

The errors reported by fsck before and after the reinstall
are broadly similar.  They might even be identical, but,
from memory, I can't tell.

It is possible that the hard drive has real errors -- after all,
os corruption prompted me to install ubuntu.  However, it
is not on its last legs -- ubuntu appears to have installed
correctly, and appears to run correctly, and I don't see any
obvious disk errors, other than those reported by fsck.

Again, are these real errors, and if so, how might I fix them?
(And, if not, for my education, what is going on here.)

Thanks for any advice.


K. Frank