[Beowulf] recommendation on crash cart for a cluster room: full cluster KVM is not an option I suppose?

[Rahul Nabar]

On Sat, Oct 3, 2009 at 11:54 AM, Joe Landman
<landman at scalableinformatics.com> wrote:

> If I were building a cluster of anything more than 4 machines (not racks,
> machines), I would be insisting upon IPMI 2.0 with a working SOL and kvm
> over IP capability built in.

Thanks for those tips Joe. I am already convinced by all the posts on
the list that IPMI is a must. No other way. All you guys seem pretty
unanimous about that much!

> For the 250-300 machine system you are looking at, you *want* IPMI 2.0 with
> KVM over IP.  You *want* switched remotely accessible PDUs, for those times
> when IPMI itself gets wedged (rarer these days, but it does still happen).
>  IMO you *want* this IPMI on a separate network. You *want* a serial
> concentrator type system to provide a redundant path in the event of an IPMI
> failure.  Problems don't go away just because IPMI stopped working.  You
> *need* an inexpensive crash cart that just works, and plugs into your PDUs.

I see, thanks for disabusing me of my notion of "ipmi" as one
monolithic all-or-none creature. From what you write (and my online
reading) it seems there are several discrete parts:

IMPI 2.0
switched remotely accessible PDUs
"serial concentrator type system "

Correct me if I am wrong but these are all "options" and varying
vendors and implementations  will offer parts or all or none of these?
Or is it that when one says "IPMI 2" it includes all these features. I
did read online but these implementation seem vendor specific so its
hard to translate jargon across vendors. e.g. for Dell they are called
DRAC's etc.

Finally, what's  a"serial concentrator"? Isn't that the same as the
SOL that Skylar was explaining to me? Or is that something different
too?

-- 
Rahul