[Nut-upsdev] Asking hard questions about the NUT architecture

[Rob MacGregor]

On 5/30/07, Eric S. Raymond <esr at thyrsus.com> wrote:
> The UPSes I use normally make *noise* when that happens :-)

Great if you're in that particular machine room, right next to the
kit, when "that happens".  Not so good if you're elsewhere.

Now, generally there's nothing you can do, even if you're right there
(unless it's just a trip switch going).  However having that 20
minutes (or however long you've got) to notify people, start switching
key services to other systems, or whatever your processes say - that's
a good thing.  Finding out that you've lost power by having the system
monitoring screen turn red - that's not a good feeling.

Later you say:

] I'm not (just) being snarky.  You seem to be kind of wobbling back
] and forth between use cases for UPS-controlled shutdown and
] remote alerts.  I agree that both actually have use cases, but
] the cases for one don't support the other very well.

Why, in your opinion, don't they?  I've found them useful, more than
once.  Having time to gracefully warn people to save work, shutdown
services and start them elsewhere is a good thing.

> That keeps coming up.  I never said I was after anyone discarding their
> hardware.

No, but you implied that.  Actually, you implied that NUT should only
look to the future and never concern itself with yesterday.  But of
course, you said that yesterday, so we can ignore that, right ;-)

> Use old hardware, use an old NUT version.

The same argument could be levelled at the Linux kernel, which
supports hardware you haven't been able to buy for years :)

More seriously, what if I have a need/desire to manage multiple UPS
with a single host, and some are USB and some are serial?  With your
plan that would require multiple systems (at least virtual ones, if
not physical).

> Or, more likely,
> use the big clanking complicated steam-powered upper layer and drivers,
> unlike the 99% of users who are using the zippy new zero-configuration
> spin of the code.

82% of all statistics are made up on the spot.

Also known as, upon what do you base your assumptions about the
percentages of users who'd be using this new Linux only/USB only
version?

> What does BSD use as a power-fail signal, then?

That I can tell, it doesn't.  However the amount of time between the
power going out and the system stopping isn't really long enough to do
anything useful except flush the disk cache, maybe.

-- 
                 Please keep list traffic on the list.

Rob MacGregor
      Whoever fights monsters should see to it that in the process he
        doesn't become a monster.                  Friedrich Nietzsche