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

[Mark Hahn]

> BTW< where a lot of people are jumping on the "Get IPMI " bandwagon, I 
> suggest getting PDUs with remote IP controlled ports is more useful.

the thing I don't like about controlled PDUs is that they're pretty
harsh - don't you expect a higher failure rate of node PSUs if you 
go yanking the power this way?

I have only seen a handful of different IPMI interfaces, but they all
were reasonably reliable.

> If you set your machines BIOS to start on power up, it is trivial to stop and 
> start machines with the PD U power, and that is definitely reliable.

huh?  we're talking about network-attached IPMI, which is fully independent
of the controlled motherboard's bios.  are you talking about those hybrid 
systems where the IPMI controller shares an ethernet port with the host?
or IPMI through a kernel driver?

> Plus , with a lot of those PDUs you can add thermal sensors and trigger power 
> off on high temperature conditions.

IPMI normally provides all the motherboard's sensors as well.  it seems 
like those are far more relevant than the temp of the PDU...

using lm_sensors is a poor substitute for IPMI.