System Update froze - UbuntuMATE 16-04

[Paul Smith]

On Thu, 2018-06-21 at 17:40 +0800, Bret Busby wrote:
> In running less on that file in that path, I fing lots of errors
> relating to sdb1, which, from memory, is the HP USB external HDD. I
> note that I can not even check to what, sdb1 points.

Well, it would be helpful if you told us what kinds of errors you are
seeing.  There could be a great many reasons.  The error messages may
or may not point at an underlying cause.  Please don't post hundreds of
lines of errors, but if there are a few repeating messages that could
be enlightening.

At this point it's definitely not clear that any of this is related to
a bug in Linux (the kernel) or Ubuntu.  It's only tangentially related
to upgrade in that upgrade is attempting to access this disk partition
when perhaps it doesn't need to: if it were more discerning it might
succeed even in the face of errors in the external HDD.

But the most likely problem here from what we can tell so far is that
your external HDD is dying or dead, or has some other hardware
malfunction (bad cable, etc.), that is keeping it from working
properly.  Apparently you normally don't use that external drive much
so you haven't noticed until now.

If indeed you don't use it much the easiest thing to do is disconnect
it.  I don't use external USB drives like this so I can't suggest the
safest way to do that; whether simply unplugging it at this point will
do it or whether you'd need to reboot etc.