[Beowulf] Mellanox UFM question

[Jörg Saßmannshausen]

Dear all,

I am a bit confused and I was wondering whether somebody on the list could 
give me a bit of advice here.

I was previously using QLogic for my QDR InfiniBand network. I got one master 
switch which got the licence for the InfiniBand installed and things appear to 
work ok. At least I cannot detect any problems despite adding switches and 
nodes to the fabric.

Now, we recently purchased a new cluster with 20 cores per node and here I 
decided to go for FDR to be a bit more future proofed as well. So I got the 
'normal' licence from Mellanox for the cluster. I got one licence per node so 
I assumed that was ok.

Now, we are in the process to set up another cluster with a mixture of older 
and newer hardware. Again I have decided to opt for the FDR simply to be a bit 
more future proofed. And this is where the confusion comes in.

Apparently I do need now the UFM (Unified Fibre Manager) from Mellanox to run 
the InfiniBand. However, the normal licence is only for up to 16 cores per node 
and I would need the more expensive exhanced licence.

From what I and a colleague of mine can see the UFM is nothing more than the 
requires subnet manager plus some diagnostic tools. 

There are two questions here:

- do we really need the exhanced UFM licence or is that just a way to make 
money?

- would the open source subnet manage work as well and would the open source 
diagnostic tools be ok?

- why do I need to pay for a licence for each node? Somehow I cannot recall 
having done that in the past.

Unfortunately, InfiniBand is not my strong side and thus I would appreciate and 
advice here. 

All the best from a meanwhile sunny London

Jörg

-- 
*************************************************************
Dr. Jörg Saßmannshausen, MRSC
University College London
Department of Chemistry
20 Gordon Street
London
WC1H 0AJ 

email: j.sassmannshausen at ucl.ac.uk
web: http://sassy.formativ.net

Please avoid sending me Word or PowerPoint attachments.
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