[time-nuts] 5370 processor boards available

Brian Lloyd brian at lloyd.com
Fri Feb 28 14:49:07 UTC 2014


On Fri, Feb 28, 2014 at 8:20 AM, Didier Juges <shalimr9 at gmail.com> wrote:

> If you use a flash-based embedded ARM board, how much is it worth to you
> that it works everyday? How much is it worth to you that you do not have to
> rebuild it once a year or once a month?
>

> I have several of them and I corrupted one a couple of years ago. It was
> not something that was on 24/7 and it was not a power outage. I turned it
> off myself and it did not come back.


OK, you turned it off and it did not come back. Sounds like a different
failure from what we are talking about. You did a normal shut down and it
failed. Of course we are going to have some number of random failures in
normal operation. S--- happens.

And I agree that, if the system has a R/W filesystem and there is no
power-fail processing provided, odds are good the filesystem will become
corrupted during power-fail at some point in time.

But has anyone determined whether or not that happens with the BBB in
question? Does it have PF processing? Is there PF detection? Does the PSU
hold power up long enough for PF processing to complete?


> Fortunately, it had a pretty much stock distribution on it and it was easy
> to rebuild. I am more careful now. Yet, my Raspberry Pi is on 24/7 and it
> survived the many storms we have had in the last 2 months (Florida is the
> lightning capital of the world, as they say)
>

And the other side is that a group of negatives does not prove the problem
does NOT exist, it only suggests that it does not exist, it only suggests
that the probability is lower than originally thought.

It is perfectly OK to not care, but most of us are used to equipment that
> powers up each time you need it and that only requires to flip the power
> switch to off when you are done.


Ah, that is not the point. I agree and I *DO* care. I want my test
equipment to power up and work EVERY time. I am still waiting for someone
to show that this is a real problem and not just an imagined problem.


> It is bad enough to have to properly close Windows (replace with your
> favorite OS, they all have similar requirements) and most open apps when
> you are done before turning the switch off on your desktop system.
>

Most of them let the processor turn off the power after completing
shutdown. That does seem like a useful approach. Allow the "power" switch
to initiate the system shutdown and then let the system remove power. Of
course, this is a hardware change and in this case the replacement CPU
board is supposed to be a drop-in replacement.

The fact that it may do it 100 times in a row and not fail is not great
> consolation if it fails at 101. It is a documented failure mode, not pie in
> the sky.
>

Noooo, it is STILL pie-in-the-sky because, as far as I can remember back up
this thread, no one has experienced an actual failure, only imagined that
it is possible, which gets back to my original question: is this a real
problem?

It is only an issue with regard to your own expectations. Do not disparage
> people who expect more of the hardware than you do.
>

I am not disparaging anyone. I am approaching this from an engineering
standpoint. When presented with a problem from a client/customer, the first
thing to do is to qualify the report. And I am not saying that it is NOT a
problem, only that it MAY be an IMAGINED problem where none exists. I have
no ego involved in all of this. I actually don't care if I am right or
wrong. I am presenting a counter thought process in an attempt to balance
the discussion. I would happily pay the $5 and then buy the beer for a good
laugh after the fact.

-- 
Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070
brian at lloyd.com
+1.916.877.5067



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