[Beowulf] Re: Building new cluster - estimate (Ivan Oleynik)

[Joe Landman]

Mark Hahn wrote:

> I'm not sure about the "most" part - HP's don't, and it looks like 
> supermicro
> offers options both ways.  all the recent tyan boards I've looked at had 
> dedicated IPMI/OPMA onboard.  all HP machines have dedicated ports.
> 
> but to me this has all the hallmarks of a religious issue, so...

Hmmm... we try to take a more pragmatic approach.  IPMI is great.  When 
it doesn't get wedged.  And every now and then it does in fact take an 
operational excursion.  Not often enough to be more than an annoyance, 
but often enough that you want to think about redundancy.  Yeah, I know, 
its strange, but if your data center is remote, and going over to it is 
hard for any reason, redundancy is a *very good idea*.

Switchable PDUs don't cost much more than plain old PDUs.  Network 
access to them is generally easy to set up.  They are a good backup to 
IPMI.  But switchable PDUs don't give you console access.  IPMI 2.0 can 
give you SOL (serial over lan, not the other meaning)  So we usually 
suggest a console server to back that path up.  The Supermicro units 
give you KVM over IP on selected motherboards.

IPMI is great, but when it fails, you lose control.  And console access. 
  If this is important (that you never lose control/console access) then 
you need alternative paths.  Given the relatively low cost of these 
control systems, its not such a bad idea to do this.

Joe



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