Re: [9fans] how to lock cpu console

[John Floren <slawmaster@gmail.com>]

On Wed, Sep 1, 2010 at 2:14 PM, erik quanstrom <quanstro@quanstro.net> wrote:
>> rio is such a minor thing to run on today's massive machines, I'm not
>> sure I really see the problem in starting it on your cpu server
>> anyway. I frequently set them up to launch into rio because:
>> 1. It's easier to fix things when I can cat /dev/kprint in a window
>> rather than have it constantly interrupting me
>> 2. I like to be able to interrupt programs
>> 3. It's nice to run more than one thing at once, have a graphical editor, etc.
>> 4. Full-screen stats is pretty
>>
>> Of course, none of these reasons matter to you, since you don't run
>> rio on your servers AND you don't think there's any reason to lock
>> them (I agree!), I'm just pointing out that graphical lockers and rio
>> in general are far from useless on a cpu server.
>
> i'll buy that.  but i think you're missing the basic reason
> that the plan 9 cpu console is so minimal.  there's no
> reason to use one, unless you are doing the most basic of
> system maintence.  and using one is not without risk.
> for example
> - you've got admin privs.  it's easy to forget any abuse this.
> - an errant ^T^Tr ^P or vulcan nerve pinch reboots the
> server and not your terminal.
>
> here are some additional reasons that rio makes life
> more difficult
> - the serial console is now useless; no fixing or rebooting
> the machine from home
> - you need a kvm port or a real keyboard/video/mouse
> to fiddle with the machine even locally.
>
> for me, the loss of the serial console alone makes
> running rio on a cpu server a non starter.
> the serial console has saved me a good 3-4 trips into
> the office this year.
>
> - erik

Those are reasonable points, definitely. Since I'm usually the only
one to use my servers (except at Sandia, where I share with Ron),
abusing my admin privs isn't a big deal.

At Sandia, the cpu/auth/file server is connected to a serial
multiplexer, so I don't run rio there. At my university lab, I didn't
bother to connect a serial line or a KVM, but the server sits right
under my terminal, so I can swap the connectors around and get a
physical console if I really need one.

Sometimes there's a good reason to run rio, sometimes it's actively
counterproductive. Now that I've admitted there might be more one way
to do a thing, I should probably go put keyboard shortcuts into Acme
or something ;-)



John
-- 
"With MPI, familiarity breeds contempt. Contempt and nausea. Contempt,
nausea, and fear. Contempt, nausea, fear, and .." -- Ron Minnich