[Beowulf] Re: building a new cluster

[Mark Hahn]

> > 4. Managed or unmanaged?
> >
> > People already recommended some switches that I will not repeat here.
> > However, I am still not clear about "managed" and "unmanaged" switches.
> > Some vendors told me that I need an managed one, while other said the
> > opposite. Will need to study more...
> 
> Do you need all those protocols for WAN networking, or are you planning to use 
> it for HPC? If you're going HPC, you don't need managed anything. The vendors 

I lean towards unmanaged as well, at least as long as the managed version
is noticably more expensive (per-port, remember).

on the other hand, I recently configured a 96-node cluster:
	- 32 nodes per rack
	- each node on a per-rack gigabit switch
	- each node's IPMP port on a per-rack 100bT switch
	- 100bT switch plugged daisy-chained to gigabit switch
	- gigabit switches uplinked (4x trunking) to a "top" gigabit switch

now, that's a fair number of nodes and quite a few ports, but since all
the switches were managed, I could fairly easily query each switch to find
the mac address of each node in each rack to build the dhcpd.conf.

I don't expect to ever use the management features - vlans, port disabling,
etc.  but it certainly was more convenient to do all this from my office,
rather than fussing around in the machineroom, sequentially turning on each
node...

regards, mark hahn.