16.04 problems - install, inactive/suspend, hard disk

[rikona]

Hello Ralf,

Friday, September 9, 2016, 1:50:04 PM, Ralf wrote:

> On Fri, 9 Sep 2016 13:05:03 -0700, rikona wrote:
>>> Simply run  
>>
>>>   sudo apt-mark auto thermald  
>>
>>> to undo it.  
>>
>>If I leave it as manually installed, does this mean it will not be
>>updated automatically? Any other implications?

> It doesn't affect upgrades. It will be upgraded the same way,
> either marked "auto" or marked "manually".

Thanks for the info!

>>What is the best thing to look at to help understand why it crashed?
>>Also, is there another way into the box at that time to do some
>>checking?

> You could take a look at log files

> Since I haven't a clue why your install crashes, I can't recommend
> what log file could be most promising, you need to google and follow
> Ubuntu troubleshooting guides.

I did look through some huge files, most of which I did not
understand. :-( BUT - In one of the syslogs there was a line with
"soft lockup - CPU#2 stuck for 23s". This line appeared many times in
the log. I didn't know what to make of it but it doesn't sound good.

Friday, September 9, 2016, 2:09:06 PM, Colin wrote:

> First try booting into the memory check and leave it running
> overnight (or similar). If that crashes or shows errors then you
> have a hardware problem.

I ran memtest86 directly from a bootable memtest86 CD, and let it run
the default test. It ran for two days and gave no errors, but it did
give a "note" stating that "RAM may be vulnerable to high-frequency
row hammer bit flips". Could this be a problem? Enough reason to
return the new memory? The default is to use CPU1.

Noting earlier that CPU number two was stuck for 23 seconds, I tried
to run memtest86 using CPU number two. The result was an instant full
lockup crash. Rebooting and trying with the remaining four cores
produced the same result. This would seem to indicate that there is
some kind of CPU problem, but I'm not absolutely sure that memtest86
will do a core selection with a late model AMD64 six core processor.
If anyone can confirm that it does, I would appreciate knowing that.

I tried running the box from a bootable Ubuntu live CD. In the boot
menu I have two ways of running the Ubuntu CD - one is labeled SATA3:
DVDRAM and the other is labeled UEFI: DVDRAM. When I run Ubuntu using
the first option, most things seem to run reasonably well for around
12 hours, but if I leave it overnight for more than 12 hours, it often
[but not always] crashes just after the first mouse move. If I run it
with the UEFI choice, it will crash a few minutes to an hour after the
boot, and every time the screen blanks for lack of activity. 

A note re the install. I wanted the SSD to be mounted as /, and the
3GB HD to be mounted as /home. I wasn't sure I could do this during
the Ubuntu install, so I formatted the HD ahead of time using a
bootable CD. The install insisted on putting /home on the SSD - I had
to change the HD to mount as /homestuff. This worked, and the HD is
usable when I boot from the SSD. Is it possible, during an install, to
put /home on a separate 3GB disk? If the HD was already formatted
another way, might there be some information written to the disk that
would interfere with the proper Ubuntu install formatting of that
disc? 

Thanks to both of you for the help!

-- 

 rikona