16.04 problems - install, inactive/suspend, hard disk

[rikona]

Hello Ralf,

Thursday, September 8, 2016, 2:01:28 AM, Ralf wrote:

> On Thu, 8 Sep 2016 11:00:10 +0200, Ralf Mardorf wrote:
>>PS: Are you sure that the upgrade finished?
>>
>>Run
>>
>>  sudo apt update
>>  sudo apt -f install
>>  sudo dpkg --configure -a

I ran the above and got the following: 0 upgrades... 15 not upgraded

>>then instead of running what I suggested before
>>
>>  sudo apt install thermald

Ran this and got "set to manually installed". Not clear to me if it
was already installed via the command, or was already installed but
just changed to a different designation of manually installed.

>>replace it by running 
>>
>    sudo apt full-upgrade

Ran the above. Did quite a lot - maybe installing the 15 that were not
upgraded by the previous commands.

> In this case iotop looks promising.
> Yes, it is, so install it and run it.

Installed iotop and ran it. Got

1%      ext4lazyinit
10%     jbd2/sda1-8
0.2%    kworker

when the HDD was mounted. When I ran iotop with the HDD not mounted, I
still got a very small amount [say 0.03%] of the above items, with a
very, very occasional tiny flash of the disc light.

The data on the screen changed rapidly and frequently and it was a bit
hard to get accurate numbers. The SSD may be so fast there isn't time
to display what is really going on. To get a better idea, I ran iotop
--accumulate. With the HDD mounted, this gave me an actual disk write
of ~2000 K/S. With the HDD unmounted, the actual disk write was near
zero.

> Now you could see if a "COMMAND" does "DISK READ" or "DISK WRITE" while
> the LED is flashing, or if it's flashing without a read or write
> access happening and you could post this information to the mailing
> list.

With the HDD unmounted, I tried running a few commands to see what
happens in iotop. It does indeed produce both disk reads and disk
writes while the LED is flashing. Looks pretty normal to me. 

> For example

> https://www.google.de/#q=ubuntu+hdd+led+continues+flashing

I decided to check out ext4lazyinit and jbd2. ext4lazyinit allows you
to quickly fire up an ext4 disk, but it does so in a way where the
disc is not fully initialized. Over time, as a background task, it
continues to initialize the disc. In my searches, this has been
observed a number of times on newly installed disks. It is not clear
to me if once the disc has been finally initialized that this process
will continue to occur. Perhaps it is something that, once done, will
not recur again. But, I did let it run for an hour, and it was still
going. On the other hand, this is a 3 GB disk and the process may take
a long time to complete. Will this eventually stop?

jbd2 is an ext4 journaling process. It may be that this journaling
process needs to keep track of the above initialization, and that both
processes will be running together until they're finished. Does this
seem like it's a possible reason for why I'm seeing all the disc light
activity, and will it, FOR SURE, stop happening at some point in the
future?

Thanks very much for the info - it was helpful.

-- 

 rikona